Well, there are a bunch of options. You could get a 3 button aux switch like the FS3X, and assign two of the switches to the Load Next and Load Previous functions that will increment / decrement and autoload the preset. If you want to be able to use an expression pedal, you could get a single button aux switch and connect the expression pedal and the aux switch with a y cable to the H9; there's a pdf with instructions about that option on the H9 support page. Or you could get a MIDI footswitch. Some MIDI footswitches send out MIDI CC messages and some send out Program Change messages. If you get one that sends out MIDI CCs, you could use the aforementioned Load Next / Load Previous options. If you get one that sends out Program Changes, then it will load a preset as active if you saved it as active, and it will load it as inactive if you saved it as inactive.