I am no diy expert, but have managed to change all vacs myself in past.
from alltech, cfr etc
usually take base of. couple of bolts. couple of j/clips on hose, take of wiring and
swap on to vac and re tighten everything.
Every 3 months i used to swap brushes on vac, lasted ages.
Why pay £58 for 30 mins work.
Obviously if your unsure, get help.
regards
Andrew