Changing from single shot to internal box

Ok, this is not my gun and just trying to find out some information. My best friend has a single shot, bolt action, s/s finish, with laminated wood stock. He loves the gun but keeps complaining that it is only a single shot. He refuses to sell it but wants to know if it can be converted to a internal box mag or hinged floor plate. I have no idea what version it is only that it is a Model 12 in 223. He cannot find any other info on the gun to say what particular model it is. Can this be converted and how? Thanks for the help.

1)the gun is probably either a 12VLP or a 12BVSS, assuming it is a varmint contour barrel.

2)-The action cannot be switched to to anything if it has a solid bottom to it, or atleast not without alot of expensive machine work. Not really worth it cause alot of guys on here would trade you even up for the action you want..
- But if it just has a single-shot follower then you can just remove the action from the stock, take the s.s adaptor out and replace the stock, which should make it a blind mag.