Help on Ruger Mark 1

TooBig

Easy way to switch the Mag pin on a Ruger Mark 11 to the other side for a Ruger Mark 1. [V]

brier-49

I don't think the mags are the same.MK1 is 9 shot,MKII is 10

Pearyw

Push and hold the follower to the bottom of the magazine and the pin should come out of the side. Reverse it, insert, and release the follower.

RCrosby

What Pearyw said, +1,
A chopstick, narrow ruler or similar piece of wood scrap works fine.