Client Menu Reference : The Metadata Menu : Detach Categories
   
Detach Categories
Detaches a selection of records from a selection of categories, or vice versa. (This is the opposite of “Assign Categories’.) (Available only, if you are allowed to modify categories.)
 
1. Select one or more records.
2. Select one or more categories which you want to detach from the selected records.
3. Select Metadata > Detach Categories. The records are detached from each of the categories in the selection.