If it is/was chambered for a typical 7mm mauser or 8mm mauser then you shouldn't have to do anything except rebarrel the gun to turn it into a 30-06.

If you just want a simple internal blind magazine then that is just a matter of cutting the mag box off of the hinged floor plate and inletting a stock to fit. But I would leave the hinged floor plate on the gun and modify it so that it is released by a push button or lever rather than having to depress the hidden button with the tip of a bullet.