Yes. Very easily actually.
But, honestly, with a 2.2 GHz processor, a GeForce 450, and 4 gigs of RAM, you should be okay for a bit. The cost would not be worth the gain.
EDIT: You don't NEED to remake the PC, you just have to get an AM2+ (Which, like I said, I can't seem to find on newegg, and I don't get PC parts anywhere else, myself).