For KPH3 driver unistalller not need. Just use console command run is as admin. Choice if Your like:
net stop KProcessHacker3 & net delete KProcessHacker3
sc stop KProcessHacker3 & sc delete KProcessHacker3
delete this driver use PH if go to Services tab, Ctrl-K -> KProcessHacker3 -> Stop and then driver STOP press DELETE button.
Do your needed uninstaller?
Of course, I can immediately name a few dozen more methods and programs that can remove a single driver, but is this necessary?