That oil will really make that grip hard to get off, as flat as the two surfaces fit......
I used a very thin blade and slipped it under the grips to break the 'vacuum' between the lightly oiled frame and the grip. The R/H grip came away with the trigger pin and mag latch pin in their respective holes......no big deal, just put them back where they belonged......along with the trigger return spring and transfer bar.
Put a dab of moly on the hammer/transfer bar cam lobe and a drop of MilTec on the pins......