Updating drawing of joined part

How can we update drawings of parts made from a joined part. We have an existing drawing of a joined part that needs to be revised while maintaining the old version. Typically I would revise the drawing and constituent parts/assy names using Solidworks Explorer and simply make the changes to the new ones. SW explorer doesn’t, however, identify the Assy where the join took place as a child of the joined part so doesn’t allow renaming with the drawing/part. ‘Saving as’ the join assy as the revised name doesn’t update the name ine joined part (a edit in context still sends you to the old one). Trying the brute force approach of renaming the join assy in the hope that the the joined part will then ask you to browse for the new assembly breaks the link to the old assembly but doesn’t allow establishing the new one.