Open the battery cover from the back of the control screen and take out the batteries.
Use the screwdriver to take out the screws on the left side of the large plastic enclosure that encased the batteries. You can now bend the enclosure so that you can reach behind it to make the repairs.
Use the crescent wrench to unfasten the nut that holds the left pedal onto the crank.
Unfasten the mechanism that keeps the pedal on the crank with the allen wrench.
Unfasten the screws that keep the plastic side panel on the wheel. Use the stubby Phillips screwdriver to get these four screws off. You will have to bend the outer plastic enclosure to reach the screws; make sure you don't break it. Remove the plastic wheel side panel.
Put the batteries back in.
Find the cord that moves the magnetic plate at the base of the wheel. Manually pull the magnetic plate back from the wheel frame. Now that the plate is unstuck, the error message should disappear.
Replace all parts in the reverse order you took them apart.