The drum should come off as soon as the wheel is removed. There is nothing holding the drum in place except the wheel. If it seems stuck the brake shoes have probably worn a groove into it, and you may have to back off the brake adjuster to get it off.
Conventional drum brakes.
The rear seat is not designed to be removed. You can remove the center seat and slide the rear seat forward.
The rear seat is not intended to be removed. You can remove the center seat and slide the rear on forward into it's place.
With the correct sized socket, obviously.
The rear seat does not come out. The middle seat is removable, after which you can slide the rear one up.
The rear seat isn't designed to be removed. If you have a center bench seat you can remove that by unclipping it, then slide the rear seat forward.
You will need to remove the inner panels to gain access.
Support the transaxle and unbolt it. You may have to remove some things to get clear access to it.
The rear brakes are a conventional drum system. If you don't have experience working one them I suggest buying a repair manual or taking it to a shop.
On a 2000 Mercury Villager : The washer fluid for the rear liftgate is supplied by the same reservoir as the windshield ( located in the engine compartment )
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