Remove the upper arm to get it out of my way. To do this, you will find the19mm headed grub nut on the arm next to where it goes into the beam. Remove the nut. If the screw comes out, no big deal, right now. If it does not, take a small pocket screw driver and pick out all the dirt in the Allen part of the screw. Use an 8mm Allen wrench. I put the wrench or socket in the screw then tap it with a hammer to get it all the way in, then remove it. Wiggle the whole arm up and down, while pulling out towards you. If it doesn’t come out, you might need a rubber mallet to help it come out.
Now, for the lower
