I found it easy to replace this on my MK" - can be done without the need to remove the fuel tank from the car - access is via the black metal cover plate in the boot (3 screws).
I think there are 2, 3 and 4 pin lift pump connectors, however the pump itself is the same on all the ones I have dealt with.
Be careful when refitting that the new pump does not fall off the unit (the rubber seals can perish with age)
You need a lot of patience to refit the big plastic nut that holds the unit into the tank! Dont cross thread this!!! enjoy!