Ford: check engine light on Ranger, purge valve, gasoline tank

Question
my 1996 ford ranger has had its engine light on since I have owned it. its been diagnosed as having a bad gasoline tank purge valve and will not pass state inspection because of it. What is the purge valve, and what is involved in replacing it? Can a backyard mechanic like myself handle this or is it better to let the dealer milk me for it?  

Answer
very easy to replace make sure you go to the dealer to get the part if not the light will come back on . go out to your truck under the hood on the drivers side you will see a black hose next to the battery box and it will be going to the intake it will have a round tube look to it and have hoses on both ends.and a plug on top.  good luck