My 96 GT temp gauge has been out for a while. I have been told it is my temp sender (or sending unit?). My brother told me its an easy install, just screws on, and I might lose a little coolant. Is this an easy install? I'm no mechanic. The dealer said its around $100 to fix. Isn't this a $20 part? I would like to try to fix it myself if possible. Thanks!