[SteveSarre]

I probably did use an impact, but that would be for speed, not for impact, if you know what I mean.

When you heat the arm sufficiently the black plastic bushing melts and almost squirts out. The circumference of the bushing has collapsed and the pressure against the arm is greatly reduced.

At that point, you can screw the tool either with a ratchet driver or an impact, and pull the old bushing out.

But if you don't use heat, there is a risk that the impact will damage the tool.

I clean up the inside of the arm, to make it easier for the new bushing to slide in. I also chamfer the leading edge of the new bushing to make it easier to get started. I also put silicone grease on the inside of the arm.

Steve