To delete a member or group of members, select the members you want to delete, right click and select Team -> Delete from SCLM.
Files in the Package Explorer can only be deleted this way if they are checked into SCLM. To delete the member from the workspace, select the Delete Workspace File check box. There are a number of options when deleting the file from SCLM. By default, the Member radio button is selected, which deletes all SCLM metadata relating to the member, as well as the member itself. If, for example, you just want to force a build of the member, delete the Buildmap.
A member can be deleted from any level of the SCLM development hierarchy.