Get 3 wire nails that fit hole perfectly. Holes are only 3mm deep so cut point off a test nail first and clean up end with diamond file or stone. When you have wire nails of correct snug fit, cut 3 to a length of about 15-18mm leaving points on. Clean up ends and put blunt ends into holes. you should then have 3 points sticking up. Get a piece of oak or similar hardwood about 1" square and about 5" long. Position middle of oak(This is your handle to give leverage) above nails and tap oak lightly with a hammer. Lift off oak, turn over and you should have 3 pin pricks indicating where to drill 3 holes about 12mm deep(must be snug fit). Replace oak over points and tap down. Tool now made. Remove rear-sight if not done already. A few drips of WD40 around plug and leave over night. Hold pistol firmly, pushing tool onto top of plug and twist.
Let me know if it works as I have a LP Mod.2. NOT made tool myself. MIGHT work. MAYBE try for loan/purchase of real thing before hand.
Best of luck...Vian.