Push the function and global buttons to enter your global menu, then scroll down to track routing. Once in there you simply push and highlight the inactive pad. If this does not solve it, it may be that you have disabled it in the DAW plugin. If that is the case you can only re enable it by loading the plugin in a DAW, going into the kit properties and clicking on the use global settings switch. Once you have enabled this you just need to select which pads you want to hear through your headphone and main outs.