Technical Guitar Question...

[Eagle131]

I just got into modern fingerstyle techniques (two handed slaps) and I wanted to buy a cheap guitar that I could beat up while I learn how to play. I found a 40 dollar pawn shop Lark (supposedly an old sub-manufacturer of Kay). The tailpiece is adjustable as is the neck. Now the string height is way high, and if I set it any lower, I get an undesirable buzz on the open D and G strings to the point where it is unplayable. The neck's got a bit of back bow which I think causes the buzzing, so I figured if I loosened the truss rod a bit, I could lower the tailpiece. And THEN I could make this cheap guitar be decent for its money. One problem I ran into though. The truss rod nut seems to be stripped. I used a variety of allen wrenches, tried several different tips, but I can't seem to adjust the d**n thing! Its getting so frustrating. My question is this: Is it possible to remove the truss rod nut somehow and replace it? I've looked into the truss rod restoration kit, but its a whopping $240 for just a few pieces of metal and a spiffy drill bit. Arghhh if anyone knows anything, please lend me some of your wisdom!