take pump out, depending on how badly stuck your cap is (it will be very tight) 20 minutes
pull pump apart...WTF? its just clamped onto a metal cradle, takes 2 seconds to take it off
then you have to modify the cradle (cut it up) so the new pump can sit lower in the tank
putting it in, well... if you manage to get the pump to sit at the right hight and get the cradle to hook back on the first time then your doing really well
you also need to get a few bolts and attach the power wires to it
and if you have mates over you will stop to have sex probably about 3 times so this will not be a quick exercise.