Do any of the tenants have leases now? If so, see if you can get a copy of the leases from your grandfather, and read over them. If they used to have a lease, and are now month-to-month, see if you can get a copy of the last lease they had before going month-to-month, because sometimes the law is that the payment dates, late fees, etc are the same as whatever was specified in the lease.
If they do have leases, you have to follow what the lease says, until the end date of the lease. If you don't want to renew the lease, you have to tell the tenants that before the end of the lease. The lease, or local law, may tell you how long before the end of the lease you have to give that notice - something around 30 to 60 days is probably typical.
One thing you may hear about is "cash for keys". This is where you go to the tenants and agree with them that they will move out by a certain date, usually within a couple of months. They meet you at the property, after they move out, and you both look over the property to make sure it's not trashed. If the property is OK, they give you back the keys, and you give them some cash. Yes, you're paying them, even though they owe money. The idea is that sometimes, doing this is cheaper and faster than going through an eviction.
Don't try to turn off the electricity, water, gas, etc to the tenants that aren't paying rent. Don't go and take the furnace or front door off of the house for "repairs" and not bring it back. That is called a "self-help eviction", and it's illegal.
I also agree with @Bjorn Ahlblad ; find the local landlord's association or real estate investment group in Virgina, and join it. Looking at where Radford is, the group might be based out of Roanoke, Lynchburg, or maybe even Richmond. This will help put you in touch with other local landlords, attorneys, contractors, etc, that may be helpful to you.
There is also a Richmond, VA forum here on BiggerPockets that you might read or post to. It doesn't get a lot of activity, but the people there should be closer to your property. https://www.biggerpockets.com/...