SO Online - Moving associates

Have an online customer that was orginally set up with multiple our companies.  They want to consolidate to only one.  However there are a couple of users who have used the system that I need to move from a now superfluous company.

Can I do this?  

I've done some testing on our own Online account and the only thing that appears to allow me to move the contact to the correct company is to delete the assocate (third option on the Delete button on the users page in Admin).  It's then not possible to give them licences on their new company with the same user ID, so documents will be lost as the user's SO_ARC folder cannot be renamed - which is probably what I would have done for an on-premise customer.