How do you pull the chain break apart on a poulan chainsaw 2150 and repair it.

The brake is a saftey item on the saw and should only be repaired by a quailified fitter, however if you should decide to do it yourslf that is down to you, the brake is a so called knee link brake, start by removing the brake from the saw, once removed activate the brake by pushing the hand guard forward untill you hear the brake come on, now remove the allen screw in the hand guard pivot ( do not remove the c clip in the side of the hand guard ), tap the pivot collers out from either side and remove the hand guard, remove the cross head screws securing the spring cover, BE AWARE THERE IS A COMPRESSION SPRING UNDER HERE, eye protection should be worn, with the cover off, pry out the spring, remover the small pin securing the knee link mechanism, using a small punch tap out the roll pin from the other side of the cover that secures the anchor end of the band, it should now come away, remove the cross head screw holding the band to the knee link mechanism. You can now replace the band, refit the the knee link to the new band, re fit to the machine, tap the roll pin back into the cover to secure the anchor end of the band, re fit the knee link pin, re fit the spring ( be carefull ) re fit the spring cover, place the hand guard back on the cover, use a suitable tapperd punch to insert through the hand guard and cover to hold it in place, now pull the hand guard fully back to load the brake, remove the punch and re fit the pivot collers and allen screw. Make sure the brake now functions properley.