Remove the 2 bolts holding the caliper on. Pry open the caliper by inserting a screwdriver between the rotor and old pads. Remove caliper and replace old pads. Slide caliper back over rotor and reinstall screws to hold cailper in place. Operate brake lever to check brakes.
Invest in a factory service manual specific to the model and year of your Softail. Follow the service manual procedures and you shouldn't have any problems. Also, inspect the rest of the brake components,replace any failing parts and replace the brake fluid.