you need the glass as well as the resin/hardener. it is a messy job.
all you do is (this is a very basic run down) sit it in the position you want it to be in when it is done, mix up the resin (make it a bit stronger than they suggest, that way it will set faster and a bit harder), lay on some of the glass, and put some resin on using a paint brush and spread around, then add more on. make sure you do it in layers. do the full area with 1 layer before you start the next.