Got some lighting kits

Basically all the coaches already have as standard copper pick ups fitted to each bogie, this feeds up to a copper strip inside small recesses in the floor of the coach interiors.  So the steps are;

1. Remove the upper body (you simply spread the sides slightly and lift it off).
2. Slip two copper strips into the recesses, this forms a connection to the internal copper strips and leaves a small upright connection.
3. The LED unit then fits into some pre-made plastic uprights which you slide it down into and which causes the upright copper connections to make contact with pins on the small LED circuit boards.
4. You fit the clear plastic diffuser into the inside of the top of the upper body, each is slightly different depending on the configuration of the car, but there are a number of tabs and clips that mesh once you figure out the correct orientation.
5. You re-fit the body onto the car base.

Then move onto the next one.

Here's a video to demonstrate it;

Fitting Lighting Units