Few bolts and a electrical connector under the wheel arch (wheel off just do the front section on the arch panel pull back )
if you want to unscrew from the top and take the whole unit out ;)You may find its just the grommet on the pump motor
You can get foam sound Deadening just dont put on the inside panels under windows etc
as said Dodo Mat goes in most places and easy to fit and mould around
Spare wheel brackets you should have2 clips on the spare wheel cover that locate into them
Dont use Felt as it fabric use and not waterproof use some soundproofing Dodo mat and as Malcolm says
use a lot of Waxoil to fill as far as possible