Swapping the battery tray / dock on your Dash is a relatively simple process, and we generally estimate it at about fifteen minutes.
Remove battery.
Removing the cover from the rear half of the frame allows us to disconnect the power wires, creating slack in the wiring to remove the tray. Remove the four screws on its perimeter and remove the cover.
Inside the cavity of the frame, you will find the plugs from the motor. Disconnect the red and black bullet connectors. Remove any cable ties or wire loom that covers the wires at the hinge.
Remove the black cover on the underside of the frame. There are 4 screws that hold the cover on.
The wiring runs through the frame as shown below. Now that the cover on the underside is off, the battery tray can be moved. The screws from the lower cover thread into the battery tray sandwiching everything together. The battery terminal dock is held to the tray with two screws, so we want to pull the tray out just far enough to get access to the dock.
Now that you can access the wiring from below, pull the wires that you disconnected earlier through the frame into the area that would have been covered. Clip them with a clothespin or something similar to help prevent pulling them fully into the frame. (Getting them back out is rather tricky, so you do want to be careful to prevent that.) Push the power wires into the frame until all that's left out is the very end of the wires and your clothespin or other keeper.
Pull the battery tray gently out of the frame far enough that you can access the dock. Be mindful of the power wires that you are also pulling and try not to yank on them.
Once the tray is far enough out of the frame to access the screws that hold the tray to the dock you can remove them. They are accessed from the underside of the battery tray. Now use those same screws to mount the dock to the new tray.
Slide the new tray into the bike while gently pulling the power wires back out of the cavity.
Run the power wires back through the hole at the henge end of the frame.
Replace the lower cover.
Reconnect the battery wires inside the rear frame sction.
Install battery and test that bike powers on.
If all is well, reinstall protective wiring loom/covering as well as the rear frame cover.
Go ride!