It can be done but it needs patience,,, a lot of patience there is a hook on either end of spring, this hooks onto a plastic clip on the outside cover first (where the cord goes) then it needs to be wound round tightly , this is the tricky bit. A pair of rubber coated gloves helps and health and safety goggles(lol). once wound the next bit is the middle of the spring need to be slotted in to the middle of the inner casing then make sure the cord is wound on correctly then push the inner and outer casings together and position the thin metal rod at the centre screw hole and replace screw
Alternatively a good midi moto specialist shop would probably fix it for around 5 pounds
Easy option buy a new 1 from ebay for about 10 pounds saves whiplash, and blisters on your fingers
andy quinn, September 2008