I acquired NOS lumbar system that I want to install on Z4M E85 recaro seats and need to remove the back panel that is one piece from leather seats (1 piece with integral headrest). Don't see ANY screws to hold in place from the bottom and only plastic attachments are for seat belt and same type of plastic piece on the other side of top of the seat - both of these have small screws. Once I remove them, is there anything else I need to be aware of to get back panel safely off? Want to do the passenger side first. Then driver seat. Thanks