Hi Gwyn,had that problem myself.Take off the black cap that is fitted to the green spool.Then,on the top face of the spool are two arrows pointing to the outside edge of the spool,these should(by twisting the spool clockwise) be lined up with the hole that the line comes out of.The spool should then lift off.When replacing the spool, line those two arrows up with the hole and twist the spool anti-clockwise about a quarter turn until the spool locks in place.Replace the black cap and you should be ready to go!
Johnboy/Cardiff, June 2009