All you need is:
a. harmonic balancer puller (you can rent of buy from Autozone for like $15)
b. black rtv gasket maker
c. air compressor/air wrench to get the pulley off the altenator (if you don't have an air compressor, auto zone will take it off for you for free).
d. bolt starter for the crank bolt (comes with pullies from steeda).
Other than that, you just need basic hand tools. It is not hard at all.
Oh, you DO NOT need a different belt as stated by WRXracer. You reuse the stock belt.