Do you just have a bad barrel that you want to replace? With the low cost of
the rifles, much cheaper to buy another.
If you're thinking of another caliber then yes, they can be rebarreled as any threaded action can be. Did you plan on staying with the original cartridge? What you have to be aware of is the fairly large bolt face size(the 7.62x54R is .567 dia.) if you are wanting a different caliber. There are a couple different rounds based on the original case, but are pretty rare.
Is this what you're thinking?
You cannot even try to justify the costs involved if that's what you want.
NCsmitty