No easy way to explain this.it is one of the jobs that takes time to learn as the only way you can do it is by feel.Lots of people remove them and come into the shop and buy new gaskets and then ring up to have someone come round and fit it for them!.some of the smell will be from the gasket but most is from the inner drum.put it on a boil wash to help freshen it up and wipe the seal out where you can.
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