With the slop you have described you should be able to slide the gear off without any problems after the bolt is removed.
To remove the key from the shaft, a small hammer and a punch should let you GENTLY tap it out of the groove. The moon shaped key should start coming out if you tap staight back on it. I prefer trying to tap at an angle to pop the front edge upward. Also sometimes helpful is to use a small screwdriver once the key starts lifting to get between the key and the shaft.
Be careful not to drive anything too hard and damage the seals around the shaft.
Last edited by Wes Scott; 07-12-2017 at 11:05 PM.
Reason: typo to vs too