Gapping spark plugs is easy and you should always verify the plugs even if they are pre-gapped.
Just go buy a gapping tool (about $1) from your local Auto parts store. It is a little circular disc with flattened edges and measurements just inside those edges. They are usually by the front desk, but you can just claim that you can't find them and let them show you and then claim that you must have been blind and walked right by them.
You use it by putting the flattened edge in between the gap and sliding the disc around until you feel resistance. What ever measurement you are at is your gap. If you want to widen it, just keep sliding the plug on the disc until you get to the gap you want.
Slade