Step 1. Remove the insole from each shoe.
Step 2. Below the insole is a “trap door.” Lift up the door and unscrew the spring with a Phillips screwdriver. Tighten firmly, but use caution not to strip the screw head.
Step 3. Re-attach the spring in EXACTLY the same orientation as the old spring. Note: Z-CoiL springs can be adjusted in 90 degree increments to adjust for pronation. Turning the coil will affect the resistance on the inside or outside of your feet and may cause under or over pronation.
Step 4. Call the Z-CoiL headquarters with any questions @ 800.268.6239