Yes, it is possible. Many have done it and it works great.
Toughest part is usually finding the barrel. The US barrels are all iin 8X57, so you need one thats not chromed lined so the chamber can be reamed out. A few members on the board (including myself) have the reamers...they can be had as a custom order from clymer as well.
The T slot on the face of the bolt may have to be opened up a bit to accept the slightly wider base of the 8mm cartridge. This can be done by putting some valve lapping compund onto a 762 or 3006 empty case or a chromed training round, and spinning it with a drill up and down the t slot until it is big enough to accept the 8mm freely.
The only other thing that really needs doing is to open up the end of the barrel bearing (muzzle cone/flashider, whatever you want to call it) to .750". Anything smaller will cause real heavy recoil.
Of course, the front cartridge guide has to be removed if the gun was set up for 7.62mm. An origional gun would have had a cartridge stop for the 30-06. I installed that on mine, but have heard from others that it really isn't neccessary other than for the last round from the belt.
Buy your 8mm on the belts. That way the belts are loaded uniformly, and you can sell the belts afterwards to recoup some (or even all) of your ammunition cost.