the coil is mounted to a bracket with rivets. the bracket is mounted with 2 bolts. unbolt the bracket and drill or grind the rivets out . the new coil comes with mounting screws.
unplug wires to coil.remove the 7mm bolt pull coil off.
with a mechanic
The 1998 Toyota ignition coil is located on the firewall, in the engine compartment. The ignition coil can be found on the passenger side of the firewall.
On my 1998 gmc safari the ignition module is located next to the ignition coil it is attached to a heat sink lift the inside engine cover off it's on the passenger side top middle of the engine.
ignition coil is broken replace $ 60.00 in Canada
'Where is ignition coil 2 in a 1998 Nissan maxima'?
http://www.ehow.com/how_4509339_replace-ignition-coil-pack-ford.html
If the coil is behind the intake, it is easiest to remove wiper arms and cowl below windshield. At least you will be able to see the ignition coil. After that have fun.
Ignition what? Switch? Coil?
Replace the ignition coil(s).
Replace it only if it becomes defective.
Most likely, replace the ignition coil packs.