It's actually very simple to replace the stock, especially if you are just putting a regular AK stock on. I'm planning on replacing mine with a Magpul CTR stock with a buffer tube.
After you your stock off (by just unscrewing the bolt underneath the grip and, after taking off the dust cover, the screw holding on the tang) see if you have a slanted or a straight receiver...plenty of youtube videos to help you out with that. That may determine which stock set you should buy, as well as whether you have a stamped or milled receiver--I'm sure yours is stamped.
Have fun! I'm new to this AK stuff too, but I've started phase 1 of modifying my MAK90...mine's got a stamped receiver and my first phase was replace the handguards...
Last edited by Zeebra724; 01-21-2013 at 06:40..
Reason: add pics
Some Maks came with an open-backed reciever like a regular AK, and with some very minor fitting, (or even no fitting at all) , you can swap into a set of regular AK furninture;
Some Maks, however, came with the reciever closed off at the back, so there's no way to fit a regular stock to it without cutting into the back of the reciever, which can be hard to do;
And some Maks came with a closed-back receiver and a little cover plate on both sides, between the rear rivets; those Maks cannot be converted easily to a regular receiver, but they CAN be easily converted to be an underfolder; they have an underfolder trunnion, and the little round cover plates (which are easily removed) cover the holes for the underfolder stock pivot.
The underfolder trunnion Maks are easy to pick out; just look for the cover plates; the others, you really need to take the thumbhole off to see which it is.