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/outside of your feet and may cause under or over pronation.
Step 4. Call the Z-CoiL headquarters with any questions @ 800.268.6239