To explain a little better, its not massively difficult, just takes a while.
You have a main brain box, and lots of wires going to each solenoid/actuator which pushes the locking pin up/down. So you have to mount these to the inside of the door skin, i drilled holes to make sure they were all straight.
Wire the brain box to the battery and groun it, job done

lots of tutorials on youtube etc
