Welcome to the forum BB
Do not despair - the air-con works....that's your worst worry out of the way.
The drains can easilly get blocked, on pre facelift cars they're only about 1/4" I.D. Havent worked on post facelift air con yet (I'm putting that off at present
)I expect the principles are the same.......
In the footwell on the transmission tunnel is an oulet vent, remove this, I think you may have to drop down the scuttle above your knees which is clipped in place and reveals the fuseboxes, remove the trim behind the vent. The vent is attached to an extension pipe which is screwed to the air con unit, remove this, this may be a bit fiddly due to wiring etc.
Be warned that you may still have a pool of water inside the air-con unit so be prepared with towels rags etc as you may get a dousing as you take it apart!
You should now be able to see inside the air con unit and also behind and below it.....lots of spaghetti in there! The drains come out each side of the bottom of that unit, plastic pipes running down and out of the car through grommets.
You will probably find a build up of soggy crap inside on the base of the unit and the pipes blocked solid, clean the whole lot out accordingly.
I pour a little water in afterwards and check for a puddle under the car where the drains exit, this proves all is as it should be.
Re-assembly is the reverse of the above procedure as they say.
If the facelift set-up is COMPLETELY different, my apologies
No doubt someone will be able to point out any differences.Good Luck
DH DOve