It's a bit of a bitch on the rear cylinder as the coil pack won't come out without the cam cover being removed as well. If you have the standard airbox that has to come off too with the throttle bodies. For the rear, undo the coil pack retaining bolt and lift the coil pack to get it loose. Undo the cam cover bolts. Now you need to gently prise the cam cover up a bit, look under it and use a flat head screwdriver to prise the collar that fits into the cam bridge that the coil pack goes through. That needs to come out too before you can lift the cover and coil out. Be careful not to scratch the cam lobes with the screwdriver!! Going back on his basically a reverse. Front will come out without removing the cam cover.