ok i am new to the ak rifles. a friend of mine got several guns in a trade. he gave me a norinco mak 90 for going and helping him with the guns. i wanted the mak 90 because i have never messed with this type gun. (i am an ar nut) the gun has a lot of surface rust. i am going to reblue the metal parts. what i need is if you can tell me or give me a site as to how to take the upper and lower forearms off. also i do not like the thumb hole butt stock. my friend gave me a pistol grip for an ak. can i put a straight butt stock on this mak 90 along with the pistol grip. i would appreciate any help. who knows i might like these type weapons and have to start buying some. any way that s what my friend said i will be doing after i redo this one. said it was additcive...thanks

922 compliance.....this is an issue if you convert it to a pistol grip config....  others will chime in with more info

Here are the 2 types of MAK 90 stamped receivers are below. The slant cut will limit your stock choices.

Yes, a bunch of silly laws regarding US made piece counts. Others who know more than me will chime in with more.