How can i blow water out of a 3" pvc pipe?

A friend has a dryer vent that exits too close to the ground, and got water in it. When you turn the dryer on, you can hear gurgling in the pipe. It's a 3" pvc line. What's the best way to do this? I'm assuming i need a 3" cap, and then somehow drill a hole in the middle, or something, and attach a fitting so that an air compressor will blow the water out? Thanks!