Isn't that a GREAT location for a plug... There are three ways that are used on that plug. One is a special plug socket that has the swivel made as part of the socket and that will get in there from the wheel well. The next is to use a plug wrench with a hex on it and then use a box end wrench to turn the socket. Another is to pull the pinch bolt and move the lower steering shaft out of the way.
Of course you could do what I know a few folks do... Ignore it , I mean five plugs are better than 6 right.....
Oh that socket can be found at Sears and some better parts stores.