Go spend a couple hundred bucks and schedule a sit down with a lawyer.

I could easily hire a lawyer with the accumulated savings from not using a PM, but was hoping it isn't that complicated and once we learn the system on this first eviction it won't be as much trouble in the future.  

Check with a lawyer, but some areas allow for expedited eviction if a drug offense is found. 

Definitely consult a lawyer before moving forward with the evictions. 

Another alternative (even if it's kind of a pain) might be to write them a check out of your personal account and then expense it back to the LLC.I'm not a lawyer, but to me that seems like it may be enough to not be commingling of funds, since the LLC is still behaving like its own entity?

If you have a guaranteed salaried positions (the usual examples are doctor, lawyer, or any other "professional" job) they can generally go right off with your new job. 

Her lease ends 8/31/21, You've already noticed her to vacate so check with a lawyer and see if you can evict holdovers that don't leave.

I'm sure you can find some good advice on this forum, but speaking with a lawyer/accountant is going to be your best bet. 

If you end up needing a good real estate lawyer here in town @Ryan Jones (Jones Property Law, Edmond) might be able to help!

It can be done without the use of a lawyer although with fairly stubborn tenants the use of an attorney can sometimes light a large fire under the real ends of stubborn tenants.