BMW is a German car maker that produces the Z4 roadster, a two-seat convertible that has a front-engine rear-drive layout. The Z4 has a low-slung appearance that is accentuated by a long bonnet and a short boot lid. A folding soft-top is standard in the Z4, but an optional removable hardtop is available on some models. With the soft-top in its folded-down position, the hardtop can be put into place so the car may be used during inclement weather.
Locate the removable access trim panels on the inside of the hardtop to the rear of the side windows.
Press down at the front of the driver's side trim panel and slide it open. Set the panel aside.
Locate the hardtop locking mechanism revealed after removing the trim panel. Insert the "L" shaped tool that came with the hardtop into the hole at the top of the locking mechanism and turn it a quarter turn in a counterclockwise direction.
Remove the trim panel from the passenger side access panel and turn the locking mechanism in the same manner. Slide both trim panels back into position until they lock into place, as this will keep them from being misplaced.
Locate the two access holes on the windshield header just below the inside front edge of hardtop. Insert the tool into each hole and turn it in a counterclockwise direction to unlock the front of the top.
Use a helper and lift the hardtop straight up from the car and remove it.
The Z4's hardtop can be installed by following the above directions in the reverse order.