Replacing 12AU7 tubes in a Prima Luna Dialogue integrated amp

Bought the until about 2-3 years ago, as the core of a new system (Dynaudio Excite 34X speakers, Rega 8 w/ Apheta 2 cartridge, Rega Aria phono amp, Oppo BDP-105D for CDs plus video).

Very happy with the system.

One of the 12AU7's crapped out, so buying a new set.  Tried pulling out the bad one, and its really, really tight in the socket.  Never swapped these out before, not sure if the just pull up, or have some cam lock to hold them in. Afraid to force it, possibly break something on the socket, it sure seems very very snug.

Sound normal?  Just keep pulling up until it moves, or ? 

Any tips, tricks or info appreciated.  (and yes, I am using the gloves PL provided for all handling of amp items.)

Yes what tooblue said. You won't hurt anything as they do fit snug. If you start rolling tubes you will become an expert. Just ask me lol. 
Thanks for the confirmation, just hate forcing stuff when I am not sure.

Have seen reference to "rolling tubes"... no clue what that is/means... but will do some web searches.'

OK, swapping the tubes from socket to socket to optimize sound.  Fun with 6 to mix-and-match...

All sorts of new things to look into and learn.
Don't swap the same or stock tubes from socket to socket as it will not make any difference. Of course I doubt this is what you meant lol?  If you like the stock power tubes or the tone the EL34 present then you might want to roll in some driver tubes for example like some Cifte 12AU7 in the front 2 slots. These make the MOST difference and Kevin Deal will tell you the same thing. If you want a little more pop or dynamics to the sound then try a power  tube in the KT family such as a KT88/150.  Or even a Gold Lion KT77 which is closer to a EL34 but with more extension and drive. Its kind of like a hybrid tube.  However, enjoy the amp as it is and make sure it is broken in well and your ears to the stock sound and then make an evaluation. One step at a time trust me :)
Have KT88's in the amp.  Looking into the TungSol KT120's.

Will look into the Cifte's.  All this is new and I get the fact different tubes have different tonal/power quantities, but I'm not a "tweaker" who really wants to get into buying boxes of different tubes and spending days plugging them in and out and looking for somewhat subjective improvements.   I'll make a few minor adjustments but for the most part am happy with the way it sounded the past two years with the Prima Luna Silver AU's and stock KT's.  Replacing with the PL Gold. Maybe the 2 Clifte you note.

But as one's gone and time to replaced figured a bit of minor research for a simple upgrade was worth looking into.

Thanks very much for the info.
Yes research is good but only you know what your ears like. I didn't care for the KT120's at all.  The 120's had too much glare or upper midrange energy for my tastes. Maybe not your tastes however.  I had no idea you already had KT88's in the amp as it usually comes stock with EL34.  Oh wait I just noticed you have the Dialogue and not the Dialogue Premium so that explains it.  So if you like the KT88 sound then what are you hoping to achieve or want to achieve? Would you like more warmth or maybe more detail?  Mullards will give you warmth and Cifte some detail and openness without any harshness. 
Before making any decisions I would call Upscale Audio and speak with Kevin or Jarod. Trust me he knows better than anyone PrimaLuna and tubes. Also look at the reviews on his website and that will also help and give you some insight. 
Was thinking they may bring a bit more depth to the mix, maybe a minor enhancement/separation to the midrange.  Not that the KT88's sound "bad", Just figure after 2 years maybe try something new.
And unfortunately Upscale Audio won't deal with International customers, I live in Australia....
Try Andy Bauman of Vintage Tube Services. There is nobody on the planet that knows tubes better than him. He tests and auditions every type of tube imaginable. If a tube doesn't meet his specs, he throws it in the garbage.
Oh I definitely understand trying something new and didn't realize you were in Australia.  I just couldn't warm up to the 120 at all. Had great bass, drive and separation however, the mids were dry and couldn't tune it out with Mullards. Your mileage may vary but I would look into a Gold Lion KT-88 or the Tung Sol KT150. The 150's tone wise kill the 120 and sound a bit more relaxed like a EL34.  Of course my Dialogue Premium was designed around the EL34 even though it can utilize just about any power tube so your amp may sound better with the 120.  Just read reviews and trust your gut :)

P.S. Andy at Vintage Tube Services does know his tubes also. I dealt with him just a few years ago. Super nice guy. 

Sorry, should have noted my location.  Things that are commonplace or at least available with a little effort in the US can be unobtanium here.  Or just incredibly expensive. Small markets.

Thanks for the tip on the KT-120 and KT-150, another case where bigger is not always better.

Will try to call Vintage Tube next week.
Found these locally,

A friend has Electro Harmonix and is happy, I've herad good things about the Gold Loin.

Recommendations?  All are similar prices, except the Golden Lion which are about twice the cost of the others.

Need to contact the shop for availability next week, everything is closed here until Tuesday.

12AU7 Ecc82 Electro Harmonix twin triode

12AU7 ECC82 Electro Harmonix gold pin

12AU7 ECC82 JJ Electronics twin triode

12AU7 Genalex Gold Lion gold pin Also known as B749 / ECC82

12AU7W Tung Sol twin triode

I'm not familiar with any of those tubes but my guess the Gold Lions would be better and not because they are more expensive.  I used to have some Tung Sol 12AX7 and they sounded nice so I would think the 12AU version would also. 
Thanks.  They only had 5 Gold Lions, so I bought two of them to test your "replace the front two with better ones" comment.  And a set of the ElectroHarmonix gold pins.  

Try a couple different configurations and see if there is noticeable tonal change, to me...
I think you'll notice a difference. Whether it's better only you can decide.