Pictured is the specific brand of Pepper mill I used.
Step 1: Tool Needed
A diagonal cutter is the only tool needed. For safety a pair of leather mechanics gloves to keep from cutting your hands during the process of twisting off the grinding mechanism.
Step 2: Twisting Off the Mechanism
This step is the hardest part. Grasp each end of the empty pepper mill and twist and pull at the same time until the grinding mechanism pops off. Gloves will help prevent injury to your hands. It takes a fair amount of strength to do this step.
Step 3: Snip the Grinding Mechanism
Using the diagonal cutters snip the plastic to cut through the ridge on the inside. Rotate the mechanism 180 degrees and snip again. These two cuts will allow the mechanism to be removed when a refill is needed but also remain strong enough so it won't fall off. Refill with pepper corns and grind away.