To remove and install the ignition switch, first, for models excluding RX-7, take out the combination switch and create grooves in the ignition lock retaining screws using a cold chisel and hammer, allowing for the use of a flat blade screwdriver to remove them. After withdrawing the ignition switch assembly, install the new switch with fresh screws, ensuring to break their heads off to deter theft. For RX-7 models, start by disconnecting the negative battery cable, then remove the steering wheel, steering column covers, and air duct. Disengage and mark the electrical connections of the switch for reassembly, then take out the stop ring cancel cam and spring before removing the combination switch. Protect the steering shaft with a piece of wood or pipe while using a chisel and hammer to break the bolts securing the steering lock body to the column jacket, allowing for the ignition switch to be removed. Finally, attach the switch body with new break-away head bolts, tightening until the heads shear off, and reinstall the combination switch, air duct, steering column covers, and steering wheel by reversing the removal steps.