It's important when calibrating the remaining heads that the camera is not moved.

Use the macro controls in Mainsail to dock T0 and select T1.

Again use the controls in Mainsail to line the centre of the second print heads nozzle with the cross hairs on the software.

Don't forget to adjust the Z-value also, the bed is lowered by 1mm after each tool change.

Enter the X/Y co-ordinates into the software.

Repeat this for the remaining print heads.