Replacing caps in Audio Research, help

Has anyone experience in replacing or upgrading parts in an older ARC amp. I have a D250mkii and was told it may be time to replace the caps.
I don't mind using a soldering iron, but I'm not sure what caps would be the the best to use or exactly which ones would be the most fundamental to change.
The amp sounds really nice but I think it is almost 20 years old and it could be time.
I know I've heard great things about Great Northern Sound but it's a pretty pricey move and also the shipping would be just plain silly.
Any thoughts or help would be greatly appreciated.
have you checked with the factory ??
alun, if you can mail me a clean schematic diagram, I'll be happy to help.

From the ARCDB, I see 9 'lytic caps in the PS, some film-types on the PS board, and 8 couplers per channel. Recapping this monster won't be inexpensive, but you knew that when you bought it, didn't you?!?! ... :-)
No I didn't check with the factory as I don't really want to ship the beast. Also the factory seems to be REALLY expensive when it comes to retubing so I am assuming the same for an overhaul.
Jeffrey, I'll try and get a photocopy of a schematic and give you a shout for a mailing address. I didn't really think that caps would be TOO much, could this be the case and do you think I should be changing all of them? I really think the amp sounds great, and the recapping was only a suggestion as to it's overall age. Once things get really pricey to repair I start to look at the viability and replacement becomes an option. I REALLY love the sound of this amp on my Proac 3.8's it is a fantastic combination and it's low input sens. make it excellent for passive line stage
why dont you have the amp tested to see if there is a issue with it before changing something that might not be needed. seems like the 20 yr rule on the large storage caps came about by someone who told you they might need replacing ?????? it would again be cheaper to locate a local repair shop( one that deals in quality products would be best) and tell them the situation. they should be able to help you .

This is true Bill, and I think it's worth a try however there really isn't anyone local that I can find who work on tube gear. I'll keep checking as I'm sure that you are correct.
I thought that if it wasn't too big a deal I'd just do it anyway to bring the amp more current, but like the saying goes "if it ain't broke, dont' fix it!"