Need to replace expansion valve on AC

I took it sevice and they told me that Imy expansion valve on the AC was clogged. What can I do to get my AC working again and not spend $500. Does anyone have any experience doing this on a 2000 voyager with a 2.4liter. I can have the Refridgerant recovered. I'd like to do this myself. Thanks for your help.

I'm also interested in this... Anyone know of or have a diagram as to where the expansion valve is? I've been (and will keep) searching the web with no luck. Haynes is a joke in regards to A/C...

Can you unclog an expansion valve?