Patch Zone 1 or PZ1 is located in the southwest corner of the stadium, under the 76 ball. PZ1 is usually active before the start of the match, up until 10-15 minutes before kickoff.
Patch Zone Two, or PZ2 is inside the concourse at the northeast corner, against the outside wall. PZ 2 is a fast and furious affair that is active during half time. If you can somehow go to the bathroom, grab a beer, and make a patch trade in that short time you will be crowned MVP for sure.