I have a Murray snowblower 627804X6 which the axle drive shaft large sprocket has a loosened chain which has stripped the teeth of the small sprocket on the other end of that chain. I need to know how to get at that secondary gear shaft, remove & replace it with a new sprocket set and chain. Can yo help me? Another supplier has already sent the wrong part so am currently dealing with huge refund process.... Please contact Wil at wilwhitney@yahoo.com I thank you in advance for your assistance.