I have changed all my exhausts myself .... with a little help from a friend
It is a bit of a squeeze underneath but very doable yourself. I would just go round and see if you can loosen all the bolts yourself..... if you can then carry on, if not then take to a garage.
You may find that some garages will let you stand around and keep an eye on what they are doing..... or even help
+ 1 on taking a visit to CS