download this -
NBA 2K12 Alternate & Wordmark Logoswhich should hopefully have the create a team logos intact (they havent changed since 2k10)
use this tool to extract the textures -
NBA2KX Mod Tool (2K12 Supported)and use this thread to figure out what textures you want to be looking at -
viewtopic.php?p=1432585#p1432585(you want the textures with numbers in the 1000s)
when you find it, hit export res, it will save a dds file that you will need to convert to a png or whatever else you want.