Wiper Arm

A customer of mine has a '93 Roadmaster and says the driver's side wiper arm has too much travel. I assume it has gotton "stripped" over 13 years of ice and snow damage. I never changed one before but doesn't look too difficult. Has anyone changed one out? And any tips on how to proceed?. They aren't too expensive and I guess others say they have run across stripped splines on the arm itself(soft spot) and have replaced them. Let me know what to expect. Thanks