How can I enhance my neighbors wifi?

Question

he lives upstairs from me and said its ok but how do I wirelessly make the signal stronger in my apartment

Answer 1

Depending on the make and model you could (Linksys) purchase a high gain antenna or http://lifehacker.com/software/how-to/bo... .

Answer 2

Does he know you plan to steal his Internet??

If so, use a repeater.  Although it may have to be put in his apartment to get the best signal.