If the parking brake was used enough you may have a lip worn into the drum. You usually have to back off the adjuster before you can get the rotor off.

You then have to adjust the adjuster to get the appropriate tightness on the hand lever. Not terribly difficult. Finding the adjuster nut through the dust shield the first time is the hardest part.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)