Currently you can only rename in session a part model to use an existing name if you perform the rename operation within the part model file. You can also rename in session a singe assy file by inputting the already existing name in the Rename in Session menu prior to the Assy Rename Menu being displayed. If you try to rename a part or assy model while in an assy the assy rename dialog menu is displayed, a "the name is already used for another object" error message occurs, and the OK button is greyed out, preventing this operation. Allow the ability to rename in session any model to use an existing name (overwrite) when using the assy rename dialog menu.
