The original brackets are held on by both bolts
and rivets. This was the most tedious
portion of this project. The rivets required center
punching and drilling out first with a
1/4" bit then to a 1/2" bit to finish the rivet.
If you’ve never used a center punch
before, it’s purpose is to score the center of
the rivet head so that the drill will not
wander on the rounded rivet head. This allows for
drilling out the rivet, not the rivet
and part of the frame. (Don’t ask). Once all the
rivets and bolts are removed, a sharp
blow with the shop hammer will remove the
offending bracket. Some of the original
holes for the old brackets will be used, along
with several newly drilled holes. The
best thing to do is to use the existing holes to
temporarily mount the new brackets.
This will allow you to use the brackets as
templates for drilling the remaining holes.