Here's a Link to a REALLY great DIY on installing Sidemarkers..
http://www.2k1civic.com/diy/sidemarkers.cfm
2k1civic.com has some really great info.. but the ppl aren't nearly as cool..
Hope this helps..
He pictures a different tool... I might just try the dremel though , that sounds like a winner...
BTW where did you get your side markers ?? Cost ??
i can't find any good ones on Ebay !! LOL