1. Remove the screws.
2. Remove the rear flap.

3. Install in the reverse order of removal.
Front flap removal/installation
Rear door garnish removalMazda 6 Service Manual: Rear window glass installation
Caution
To prevent the sealant from cracking or the glass from being
pushed out by air pressure if a door is closed, open all of the windows and
leave them open until the sealant has hardened.
1. Cut away the old sealant using a razor so that 1-2 mm {0.04-0.07 in}
thickness of sealant ...
Mazda 6 Service Manual: Auto Lock/Unlock Function
WARNING
Do not pull the inner handle on a front door: Pulling the inner handle
on a front door while the vehicle is moving is dangerous. Passengers can fall out
of the vehicle if the door opens accidentally , which could result in death or serious
injury.
When the vehicle speed exceeds 20 ...