Hi, I am fairly new to Logic Pro, I am using sounds from a Roland GR1 guitar synth. Two instruments for GR1 has been setup in the environment and I can select the sounds 0 to 127. I have a second instrument setup for the rest of the sounds. How should I set the boxes at the top of the instrument list to select as the 2nd bank.

I don't know the GR1, but in the manual there should be info about what kinds of Bank Change messages you need to send to the unit. Look in the MIDI documentation for the GR1. If you find it, post back with what it says (or if you can find the manual online, post a link) and we'll take it from there.