How do I remove back rest to remove seat to access battery?

You need to remove the seat bottom first to access the lower attaching points.

Know this is an old post but if someone else needs to know how to get to the batteries on boreem jia remove the nuts at the bottom of the shaft holding the seat where it connects to the fiber glass frame and then remove seat and shaft and then four nuts "2 on each side" under the feet rest, you may need locate the tops under the boreem label by peeling it back to hold while untighting that's it, now you can slide the housing to the side be careful of your wiring only enough room to access and remove batteries. You will have to either cut or use soldering gun to free up the wires hope it helps

The speakers should be able to be accessed through the trunk without having to remove the rear deck

The seat base just pulls up. this gives you access to 2 5mm aleen cap bolts to remove the back rests.

under the hood or in the trunk

Access the trunk via the back seats, remove the rear seat base first then the back rests to gain access to the trunk

Head Restraints Removal

1. Unscrew front seat head rest guide rod retainers (610A18) .
   

1. Pull up on front seat back head restraint (611A08) . Compress foam in area of front seat head rest guide rod sleeves (610A16) .
   

1. Remove front seat back head restraint positioning springs. Pull front seat back head restraint up and out.
   

Installation

1. Slide front seat head rest guide rod retainers onto front seat back head restraint posts.
   

1. Compress foam in front seat head rest guide rod sleeve area. Install positioning springs on front seat head rest guide rod sleeves .
   

1. Insert front seat back head restraint posts (notches on posts facing rearward) into front seat head rest guide rod sleeves and push down to engage positioning spring.
   

1. NOTE: Front seat back head restraint must operate smoothly throughout its range of travel, must remain in any fixed position, and must not be freely removable from the seat back. If any of these conditions are not met, check for proper installation of positioning spring onto front seat head rest guide rod sleeve .
   
   Tighten front seat head rest guide rod retainers onto front seat head rest guide rod sleeves .
   

1. Adjust front seat back head restraint by applying hand pressure, either up or down, to center area of front seat back head restraint .
   

The lower seat cushion, the back seat rest, the side trim panels and the package shelf all have to be removed to access the rear speakers.

Head Restraints Each front seat is equipped with dual-post design front seat back head restraint (611A08). The front seat back head restraint is installed as follows:

• It travels on dual posts which have notches to engage a spring-loaded catch in the guide.
• The front seat back spring assembly retains the front seat head rest guide rod sleeve (610A16).

• The front seat back head restraint is adjustable from its normal position to a raised position of approximately 25 mm (1 inch).
• Pull up on the front seat back head restraint to raise it. Pushing down will return it to its normal position.

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Removal

1. Unscrew front seat head rest guide rod retainers (610A18).
   

1. Pull up on front seat back head restraint (611A08). Compress foam in area of front seat head rest guide rod sleeves (610A16).
   

1. Remove front seat back head restraint positioning springs. Pull front seat back head restraint up and out.
   

Installation

1. Slide front seat head rest guide rod retainers onto front seat back head restraint posts.
   

1. Compress foam in front seat head rest guide rod sleeve area. Install positioning springs on front seat head rest guide rod sleeves.
   

1. Insert front seat back head restraint posts (notches on posts facing rearward) into front seat head rest guide rod sleeves and push down to engage positioning spring.
   

1. Tighten front seat head rest guide rod retainers onto front seat head rest guide rod sleeves.
   

1. NOTE: Front seat back head restraint must operate smoothly throughout its range of travel, must remain in any fixed position, and must not be freely removable from the seat back. If any of these conditions are not met, check for proper installation of positioning spring onto front seat head rest guide rod sleeve.
   
   Adjust front seat back head restraint by applying hand pressure, either up or down, to center area of front seat back head restraint.