Some others have given some good options. I am going to give you a darker one.
Drop one of your players from the game.
Painful I know. Controversial absolutely. I had to do it in my game (I had 8 people wanting to play, and I dropped 2). I hated the agonizing decision of choosing how to lose, as they were all my friends.
And....it was the best decision I could have made for that game. I have run games with large parties, and ones with smaller ones. Smaller groups run better. Now you can manage large groups, I'm not saying you can't. But there is a crispness, a good pacing, and just generally more enjoyment per time spent with a smaller group.
It feels so terrible wrong to consider, but for everyone else playing, it was the absolute right decision for my group...and it might be the right one for you too.