Unclog a/c drain tube

The drain tube on my 2005 Buick LaCrosse seems to be clogged. Where do I find the drain and how do I unclog it? Thanks.

First there are two drains.  One is the A/C drain and the other is the drain for the area in front of the windscreen (where leaves and stuff can get in).  Since I don't know your car, I can't give specific recommendations. 

Once you find the drain, you may use a little compressed air (don't over do it, or you may make a small problem into a mid size problem) or some string trimmer line, but take it easy as that also can cause damage if you are not careful.

Good Luck.

It usually protudes just in front of the firewall on the passenger side.