hmm problem is I don't want to spend any more money on the guitar (was quoted $150 for a setup and new strings though I have to send it off to a shop so I won't be able to see how they do it).
At least take a look at ESP owner's manual available for download. However, I never felt confident to try any adjustments based only on it. I believe that you can find lots of written material online, as well as some videos.
According to some books (e.g. Dan Erlewine's), if you tighten or loosen the truss rod too much you can cause severe damage to your guitar. But if you are really going to do it by yourself, do it on small increments (like 1/8 to 1/4 turn each time), tune the guitar if necessary and check the result. Also, some recommend that you should put some pressure against the headstock (as you were trying to backbow the neck with your hand) while tightening the truss rod (same reference here).