To reset your stats and begin anew, please try the following workaround:
nagivate to the KF2 appdata folder
go to the Start Menu and type in %appdata% or
navigate to \Users\USER\AppData\ then select your KF2 folder
delete this folder to wipe your local savegame information
Relaunch the game through Epic Games and tell it to use your local save, which should warn you that no files are selected. Then your perks should be reset.
