Mastersound Tube amp


Trying to swap 845 tubes on Mastersound 845 Compact amp but having difficulty removing the 845 tube. I don't want to use excessive force just in case there is a specific way of doing it. 
Does anyone know exactly how to do this? The manual is completely useless here. Does it need to be turned in a particular direction before pulling out? 

I tried contacting the distributor but have not heard back yet. 
ei001h
The 845 in the Mastersound move sideways! You have to look inside and see the stripe and where the notches that are on the tubes line up, and GENTLY move them SIDEWAYS!!!! (NOT back and forth by any means!!!) till the notch reaches the hole on the tube socket....
I forgot whether it clockwise or counter clock wise... I used to own the EVO 845 and have swapped tubes quite often.... You have to be very careful with those sockets...
kot, is it sideways or counter clockwise ? I’m confused. Look inside where and which stripes ? Do you mean look inside a tube ? There is nowhere else you can look inside. Please elaborate 
You simply turn it COUNTERCLOCKWISE and turn it about a 1/4 turn and it will release. Do not wiggle and pull as mentioned above.
It doesn’t turn counterclockwise, at all. I’ve been getting many responses and they all contradict each other. Please respond if you own the amp.