Prepare two of the A4988 Stepper Drivers by removing them from their packaging and sticking the heatsink to the black chip.

Make sure that the heatsink is not touching any of the pins. Orient the fins of the heatsink as shown.

The kit also includes one spare A4988 Stepper Driver.

Z-Axis Stepper: Adjust the trimpot so that flat side is pointing towards the bottom left corner as shown in the second photo.

E-Axis Stepper: Adjust the trimpot so that flat side is pointing left as shown in the second photo.

Fix the two Stepper Drivers onto the the control board as shown in the Z and E0 positions.

Make sure that the screw trimpot side of the stepper drivers is pointing towards the touch screen. Installing a stepper driver the wrong way round will destroy it.