Can I mod this?

[SilverEcotec]

I have had many green lasers in the past. Most not very powerful. I bought 3 of these and they seem really nice! I was wondering if anyone can tell me how to pot mod these!

http://cgi.ebay.com/Best-Powerful-5...34|39:1|66:2|65:12&_trksid=p3286.c0.m14.l1318