Ruger P89 trigger plunger removal

[Whirlwind06]

Anybody know how to remove the trigger plunger and spring assembly from the frame of a P89? There is a pin on the the outside of the frame that holds it in place. But it does not look like a roll pin.
I have my P89 almost completely detail striped. The only thing I don't have off the frame is the slide stop and the trigger plunger assembly.

 

[Whirlwind06]

Well, I found a take down guide on ebay.

Thanks for everybody's help.