To start off, grab your Stampede's battery tray and remove these six screws on the bottom.

Once you remove the screw, separate the bottom of the front of the battery tray (the part that goes in the stampede first) and slide down the metal piece on the left side until it looks like this.

Next, grab one of these:

Put the Red wire into the gap between the battery tray and the metal piece. Slide the metal piece up, and push the battery tray back up. Also, wrap the black wire around the coils on the right side.It should look something like this:

These battery holders hold 8 standard batteries. They have connections on the side to connect to the adapter.

Carve out the inside of the the battery tray to hold the battery holder.

You can use a dremel to cut out the plastic. After, connect the battery holder and the adapter and put the battery tray back in the Stampede and enjoy the added power!