*heart attack* - oh, you mean how to modify your computer for thirty pounds, not buy your guide for thirty pounds
I have just done the easy option on the modding thing - tbh it's more customizing. Modding would be sitting down with a dremel and redesigning stuff instead of just adding pretty lights etc.
I've added 2x12" internernal blue cold cathodes with switch hole cut and flushed into a front bezel behind the door. New fans at front, had to pop out the front facia to gain access to it, then re-route the wires. Window decal, radiation sign (looks cool I think.) Basic bit of cable sleeving and then the little things - AMD sticker etc
It was a nice case to begin with, I just wanted to make it look a little bit different, besides I hate having things standard - and it is overclocked a fair bit so I wanted to subtly hint at that, too!
Future plans are cutting an 80mm blow hole in the top - got the tools just need the nerve to do it. Wanting to put a ~30CFM blue LED sucker at the top, behind some kind of lazer cut fan grill.
After that, and I have wasted my cash buying the mods I can't make/make look good, should be a cracking case.