I need help fixing up my rusty savage 775a 12 gauge

[222rem]

I have a Savage model 775a 12 gauge. Not a great gun, I know. It's very rusty inside and out. The action is still working but rusty as well. I'm comfident in removing the rust from the outside of the gun and inside the barrel, but not sure I'm ready to disasemble a semi-auto. It's not worth it to me spending money at the gunsmith on this one. If I remove the wood and soak the rest in a gun safe rust removing product and remove what rust I can, will it be dangerous to fire with rust left inside? How hard is it to disasemble? Where can I find a repair manual on this gun? I am not oppsosed to agressive product that harm the finish, I plan on painting it camo. In thank you in advance for your advice.