OK - I found this in another forum: "There are two adjusting nuts on each backing plate. Turn the nuts in a counter clock wise direction to loosen. If you take off the wheels, there are a few screws holding on the drum."
However, I do not see or cannot find any screws holding on the drum. https://ibb.co/72pCCZL

If at first you don't succeed . . .
er . . . then skydiving may NOT be for you!

1946 Chevy 1.5-Ton Flatbed Completed
1946 Chevy 1.5-Ton Just getting started