Do you mean the spark plug?  If so I can't see how it could be removed with the tank still in place.  BTW it's not that difficult to remove the tank.

Snot hard. The side the vent tube goes through, gottsta chop the hole open, remove the front bolt loosen the rear, swing it out. The toolkit plug socket will go in. Or,you can get a socket at Lowes,
I use a spark plug wire,well,the rubber, stick the plug in, use that to start a plug.

I don't remember all of what it took to make that access work out. Seems like I left the front bolt in the head, cut off, so the trim piece had to be lifted in the front, loosening the back one made it possible.
You might be ahead to pull the tank to eyeball everything and access the bolts you need to get to and pull the vent tube to get the trim off and cut it. I don't think I could have done it with the tank on.

Thnxs y’all