Rig manager/factory profiles

You can do it through rig manager software. Highlight them all and press delete.

I’d back up your rig first though just to be sure. You also could set up a folder in rig manager and drag all the profiles to it from the kemper, just to be on the safe side as well. There are some great stock ones which could be tweaked to your liking so it would be a shame to lose them.

You might want to simply mark the ones you like as favorites, and then just display the favorites. It will save you time, with less chance of remorse later on.