SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I have just bought a house in South Central Florida and the previous owner installed what appears to be a very nice sprinkler system by RainBird with 6 zones. I have never had a sprinkler system before and would appreciate some advice. First off the system is 9 years old and works from well water. My initial question is regarding a popup rotating sprinkler head that does not rotate,it pops up and waters and it sometimes does not go down either. I read somewhere on this forum a post years ago where the writer took out the head and washed out the base and got out a lot of sand and dirt and now it works fine. My ignorance is vast and I would like to know how to get the rotating sprinkler working again.

Thank you Wet Boots, as a newbie to this, how does one replace the head? are special tools necessary? do I have to dig it out of the ground or is it an above ground process?
Sid