Lawnmower won't start Leaking oil from filter?

I think I may have put too much oil in my Lawnmower. I have a Yardman mower. Is there anything I can do to get it started? I changed the spark plug, new gas. I took spark plug off and pulled rope a few times. Changed filter. Last time when I put spark plug back it gave me a cough but that was about it. Any suggestions greatly appreciated. ThanksLawnmower won't start Leaking oil from filter?
Empty some oil until it is at the proper level