Adding Auto Bed Level to Prusa i3

I have a Prusa i3 with a Wades Extruder as pictured. I want to add auto bed level to my current extruder and want input on people who have done it before. I am looking at using a Endstop with a micro Servo to move the probe up and down. Running marlin firmware, how hard is it to do?

its fairly easy if you are familiar with firmware, I've done it on my Folger junk i3 in couple hours, the whole setup took me a day as I was upgrading hotend, converting to bowden from direct, replacing the boards, belts, rods, heatbed, almost completely rebuild it, but the auto bed level part took little of those time

Prusa i3 auto bed leveling