sampled a radio snippet on the ‘peek’ drum kit. how do I deleted the sample to get the original drum engine back fro 'Peek"
Just go in and select Peek again for that preset spot. If you don’t hold down the number key and save your sample as a snapshot, it will go away if you choose a drum kit in it’s place.
Shift+Drum button to reset to the saved patch. Also works for synth.