We'll get you through it mate, it could be worse. I elected to strip the fretboard and reshape the neck tenon of my first build, having not done any form of wood work since highschool.
The good part about it, is you can make up a template in 6mm or 9mm MDF based on your existing routed cavity. You then adjust that template, to suit the actual pickup, and then you can rout both the required adjustments at the same time.
What you will need to get though is a router bit with a guide bearing above the cutter head. Probably a 1/2" or 3/8" one would give you a nice fit to the curves of the cavity.
EDIT: The screws should locate into threads on the PUP to give you height adjustment relative to the strings I would assume? Or am i wrong in saying that for the TL Kits? TL Veterans, Assemble! Your wisdom required!