If I can crack the AES, how do I crack the wifi
If you "crack the AES", a very hypothetical assumption, then you could simply parse the WiFi packets and decrypt the messages that are being send.

Cracking AES is however considered impossible. AES-256 is even considered secure against attacks that involve (somewhat less hypothetical but still unavailable) quantum computers.



Note that even RC4, which was one of the reasons that WEP was cracked, is considered pretty secure when used correctly. Generally you are better off attacking the protocol or protocol implementations.

If you really want to attack AES itself then side channel attacks are probably your best option.