Same thing happened to my Homelite trimmer model no. hlt26edn
You need to remove all the screws holding the plastic housing and then disconnect the off/on switch wires and the throttle cable. Be careful when you remove the pull start assembly, there is a coil spring which may let go suddenly.
I disassembled mine, recoiled the spring and re assembled everything correctly, only to have the same thing happen after 5 pulls on the starter.
I guess I need a new part?
Nat, November 2009