Cant see why you cant do it yourself, but it probably is best to let a garage do it as they have much more experience etc. If you do it yourself the hardest bit will be gettin a good colour match, its even more difficult to achieve with your typical aerosol cans.
kennyvalver on here did his himself at college but he is doing a bodyshop course. My advice would be pay to get it done professionally. And if you are doing it yourself remember preperation is the key.
Yer i was going to point out you'll really need to get an air compressor, im not sure how much they are to rent, but they aint cheap to buy. You'll need a dust free atmosphere etc too. and as pointed it, you may find it hard getting a good colour match
im planning on respraying my star silver corsa gsi replica the end of april! im looking along the lines of gun metal colour... does any1 know what the gsi colour is?
im having mine done professionaly, its about £600 but well worth doing as they have baking ovens etc