Providing prior owner 90 days to vacate

[Eric Petersen]

Maybe not the smartest move, but it got the deal done at far below market prices so I am happy with that. I said they could delay move out for 90 days. No rent, just pay utilities, HOA , etc. I want to make sure that they GET OUT on time and that I preserve my rights. Property is in NV.

1). This seems to be considered "at-will" and there is no lease agreement nor are they paying me any rent.  Should I file notices when I get close to the final day?  

2). From my read, it looks like I can use a 5-day "no cause" notice as they are basically a holdover tenant, with no lease and no payments so I can go with the shortest notice period.  Does this seem right?  Should I use a 30 day even though I can use the shorter? 

Basically I just want to be sure I can get them out if they dont move on time so I want to file any and all notices that are appropriate.  At the same time, I dont want to send them something that implies we have a different type of relationship.  

Any and all advice is welcome.  90 days isn't up for another 62 days, but I want to start getting my ducks in a row now.  Is it better to use an eviction firm or just prepare the notice from online sources and use the sheriff to deliver?

This is the first deal I have done like this and if there are "better ways" to do this, I would love to hear them as well.