Get somebody to hold the inner drum or use a large spanner or bar to hold the spider steady while you undo the nut. However, if you need to ask this, I suspect you may not have the technical knowledge and/or skill to do the full job. The front of the outer drum has to be removed to access the inner drum and remove it to work on the bearings. Depending on the machine, this can be as (relatively) simple as removing the front panel to virtually stripping the machine if the case is spot welded. You may also need a new (drum) seal if you are succesful and complete the job.
Paul Higgins
May 2007