I'd figure out where to mount the slides on the frame and mount them there, then figure out from one edge of the plasma table how far the edge of the drawer glide portion (taken out of the part already bolted to the frame) needs to be, cut a piece of MDF that size and use that to locate the part that goes on the drawer. With careful measurement and correct calculations you should be able to get within a 1/16 of an inch and using the board will ensure that it's parallel to the edge of the plasma table. It's a method I've used before.