How do I remove the climate control unit from the dash?

With great care, grasshopper- why would you want to do that?!

To send it out for repair service.

It's a little too complex to post here. Remove trim panels, screws from the face plate, vacuum lines, wire connectors (most of which may be accessible from the driver's side of the underside of the dash. The only repair service that assembly can require is replacement of the fan control switch. You can do that yourself. What's going on with it?

The a/c and fan only blows out the defrost.I understood from other research that the fix is internal to the control unit (the one with the buttons). I was sending it off for repair.

Be sure to check the vacuum lines, check valve and reservoir under the hood before you go to all that trouble. The system is designed to default to the defrost position in case of a loss of vacuum. That's usually the problem - not always - but usually.

What can cause the vacuum loss?? When I first turn on the a/c while idling, the a/c blows out the vents like it's supposed to. As I get about 35 mph it changes to the vents only. Even when I switch to vent only at high speeds only nothing comes out the vent. The a/c pressure seems good using a guage with an home type kit.

At least you have slowed down on your desire to take out the climate control unit- we know now that there MIGHT be another cause- you can check all your vacuum lines, in the meantime can you see up under the dash by taking out some easy panels? If there is just one door which switches the vents to defrost, that would be the one to look at- I HATE the modern "climate control" systems- they used to be so simple

It was the climate control unit. I sent it out for a rebuild to a place on E- Bay. It cost under a$100 for the rebuild and works GREAT! The unit is easy to take out and put back in by myself.

I also might add that the it was really easy to do the vacuum lines and electrical into the a/c unit head. I have learned to take a picture with my phone at each step so I don't mess things up putting things back together.