Need to replace internal Regulator in alternator

[Bullcrappy]

Hello, I have a PowerMaster pwm-27294 alternator with an internal regulator and the regulator has tested bad.

I have not opened it up yet but would like to replace the regulator. as this is a nice 100amp unit that is polished.

Can this be done?

Can i get the part at local Napa etc or does it need to be ordered from Summit or PowerMaster?

thanks for any help.

Bull