Cover the shoes in chalk, spin the wheel and apply the brake a few times, then remove the high spots. This is where the chalk has rubbed off the shoe. Do this until all the chalk has been removed.
Alternatively, ride bike and gently apply the brake, do this about 20- 30 times and it will bed in. Doing it this way will not glaze the shoes up, glazing is where they harden due to heat, thus making them much more difficult to bed in.
However before you can get an efficient brake you should have the drum checked for ovality. Usually costs about £30 to have it skimmed if necessary.
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