U20 Valve seal replacement tool

[Tom PRATHER <tomet9@sbcglobal.net>]

Hello datsun gurus,
   
     I have finally worked up the courage to replace my worn valve seals via 
the rope in chamber method. Does anyone know which tool co offers the proper 
tool that allows the removal of the keepers? Or can this be done with ordinary 
tools . I've heard there is a impact tool that pops them off easily. Your 
feedback would be appreciated.
   
                Thanks, Tom