Originally Posted by bkylem
I agree with Dreamcatcher in that it has to be in a written format rather than verbal. It may sound a bit heavy, but I would consider a registered letter as proof that they did receive it. Hopefully you will never need the documentation, but without it they could simply say that they never received it.
Keep your writing on a professional level and as purely a matter of business.
I also might use this experience to create a nice set of rules/requirements for the next individual to sign.
My very best !
This is tough as it seems to have started out a casual, verbal agreement. Unfortunately these things start this way but often end badly. I agree, do everything in writing when you ask them to leave but I think "a couple of months" will make them think you aren't serious. I'd write a formal letter and give them an exact date to move their horses and if you ever decided to do this in the future I'd suggest using a true boarding contract.
Here's a place for free equine contracts: Horse Legal Forms
You can download them and modify to your own needs. After you tell them to leave keep a very sharp eye on what's going on. They may resent being kicked out and damage thing or do something to your horse!