I did this over the summer ot my '02 mxz
it is very easy as others have mentioned... remove the seat...
its all there even the dimples where you have to drill into the tank..... use a hole saw just big enough for the float to fit through... i never did a overnight test to see if it leaked or held the gas... just put gas in it once completed and crossed fingers...
as for the wiring.. it is already there... plug in tank end and then once gauge is installed there should be a plug in the dash area for it as well...
good luck
love