The fuel line is 'rotten" in my Weedeater. I can not find how to remove the old fuel line. I have the manual, but there isn't information regarding replacing the fuel line.

Hi,
I could not look up the parts manual for your machine, but a way to try is to take the replacement line and cut it at a sharp angle at one end, spray it with some lubricant, feed it to the hole in the tank (possibly with the aid of a piece of wire) until a tip of the angle end protrudes and grab with a pair of pliers and tug sharply.
Peace,
Clarke