That's actually quite easy and straightforward (if you've read the manual): tap the right footswitch (the unlabeled one) three times until the display shows "guitar preset mode". In this mode, the left / 2nd from left (rec / play) footswitches select the previous / next guitar preset. Arrage your user bank accordingly and you're all set. Make sure you explore the other modes as well, because you can select (your own) pre-recorded loops via footswitch in the same manner and play them live. Excellent and lots of fun!