By Nudua at http://nudua.blogspot.com
Mega Man Anniversary Collection GCN Button Patch

This patch switches the A and B buttons.

1) Extract the contents of the rar file to the same folder as the image.
2) Run patch.bat (just make sure your image is named iph-mmac.gcm)
3) The newly created file will be called iph-mmac-fixed.gcm.
4) Burn the iso and enjoy the collection the way it's meant to be.

Alternatively:
1) Open the command promt and navigate to the folder.
2) xdelta3.exe -d -s iph-mmac.gcm mmacfix.dif iph-mmac-fixed.gcm
3) Burn the iso and enjoy the collection the way it's meant to be.

Note: xdelta3 will not patch if you don't have the correct image file.

Other info:
Image MD5 before patching should be: 8218316438e841364b980b5b95a54a78