About 1 or 2 hours work. You'll need to remove the glove box, then you'll have to remove a few cables and the ecu to make some room. Then you will have to unbolt that big round part and (about 3 or 4 bolts al around), then slide the evaporator to your left and you're done.
If you have any questions just pm me or send me pics and I'll help you.
Good luck !