Marilyn,

The easiest procedure is to work from the oven cavity. Unplug the power cord or turn the power off to the range. Remove the oven door, oven bottom,anf flame spreader etc. dismount the igniter from the burner tube. There should be a metal "shield" held in place by a screw mounted to the oven wall, that the igniter passes through. Once the screw and shield is loose you can slowly extract the whole assembly, and unplug the wire harness connection. and reverse the procedure and test the igniter operation. Just remember, be careful with the new igniter, they're pretty fragile, and can crack or break easily.

Good Luck,
:) :) :)