fuel pump swop ?????

hi need to do a fuel pump swop but never done owt like this before
is this a easy job
what bits do I need
got pump
and timing belt
new water pump gasket (got 2 ???)
this is in a series 3 told its xmod due to light green paint
after buying wrong pump 1st
chap told me it was 2,25 to find out was 2.5na
and the price he wanted he told me to put a 200 tdi

many thanks for any help paul

If you google it, there are loads of illustrated guides to the job. the biggest problem is usually removing the crank bolt, due to the high torque.