I am an owner/landlord. I do not live in the Unit.

Rented to 4 different roommates. All month to month.
2 seem to be using drugs. There has been an incident in the community
They have been paying their rent on time.

What is the fastest way to get them out.

West Palm Beach, Florida

Since they are month to month, you can give a month's notice to vacate, in writing, to each one. It might be good to hand them to them with a witness, and send them certified mail, and post one on their door. If they don't leave, then you file for eviction. If they retaliate with damage (keep an eye on the place or hire someone to, or ask a neighbor there to), then call the police. You don't need a reason to terminate their month to month, and shouldn't give one based on allegations.