The battery box for this scooter is easily taken apart to replace the batteries. Remove the battery box form the scooter and turn it upside down. There are 8 screws which hold the 2 halves of the battery box together. The screws require a long shaft Phillips #1 screwdriver to remove because they are at the bottom off long plastic round recesses in the battery box. Don't forget the 8 lock washers under the screw heads.
This scooter takes 2 batteries rated at 12 AH. The best type are AGM batteries (advanced glass mat). When you have the battery box apart, turn it right side up and pry the batteries off the velcro. Note which terminals are connected to red (+) and black (-) on each battery, The batteries and the terminals will be marked. Re-use the velcro by putting it on the new batteries to keep them secure in the box. Connect the four fast tab terminals to the batteries and push down on the batteries to get them to stick to the velcro. Turn the box over and install 8 screws making sure a lock-washer is under the screw head. Using your long screwdriver tighten securely. Plug in and test scooter and charging of the new batteries. Hope this helps.

8 screws 12 or 17 amp AGM