replace spark plugs

I don't know where there is a free manual with a picture, and I don't think you'd need it. The easy way to disconnect the plug wire is by first detaching the wire from the ignition coil, then unplug the wire from the spark plug by twisting and pulling on the boot carefully. Then remove the plugs. When installing new plugs, check the gap for the proper spec using a wire feeler gauge. The spec should be on the information label under the hood or in the owner's manual. If neither are available, get the guy at the auto parts store to look it up for your particular engine. Sparkplugs are often not gapped appropriately out of the box, you need to set the gaps to the specs for your particular engine. Torque the plugs to the point that the gasket crushes a little, they need to be real snug but not dead tight or you will never get them out again and you could damage the soft aluminum threads in the head.

This is a 2.7 hour job for an experienced tech. Be careful on what you take on if you are not experienced