You must disengage the ratchet on the star wheel adjuster to turn it "backwards". A small-diameter, long screwdriver works for me.
Also, my front drums were riveted to the hub. I ground the heads down and pressed the rivets out so I can check or work on the brakes without exposing the bearings/spindle.

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If you can't fix it with a hammer and screwdriver, you need a bigger hammer.
1965 Chevy C10