First you'll need some basic electronic and hand tools
Desoldering Iron (ya know you'll mess something up),
Some things you'll need
Lasers @ ~660 nm
A big hairbrush
Box of electronic junk (for switches, wires, pots, etc)
Circuity to drive the lasers (option depending on the setup)
A sense of adventure!
Also most of my information came from this article that I found floating around somewhere online.. Laser hair therapy
It filled in all the gaps for figuring out what needed to happen.