You will need to give everyone notice of your intent to change the rental structure when their lease expires, and then fill it as you normally would.

Or wait until a lease expires and give a 30 day no cause notice.

I recently purchased a property with an existing tenant whose lease expires in next year.

When the current lease expires, you could increase rent, and tie it in with a discount.

My father in law, who lives in town, just recently let his realtor's license expire. 

This is why so many certificates expire every year, because it is simply not worth applying for the deed.

And our property management company said it is harder to manage because it is by-the-room leasing which requires specialized software and also requires higher deposits due to higher expected damaged and also most of the leases expire at the same time around June/July.Additionally I was told that the you need to provide more amenities and the ones you provide have to be of larger quantity.

Now if you have already sent him your assignment and OTP he knows when your contract will expire.  

I call a month ago as I see the check will expire and had the retirement plan administrator reissue the check (payable the same way)Someone today just mentioned I had 60 days to deposit the check and complete the transaction -- I found the IRS website where it talks about that - but from my interpretation they are very vague - one part of the site makes it seem the 60 day clock is if you are paid the funds directly ( I was not in the case or at least in my interpretation) -- another part of the site makes it seem any eligible rollover is subject to the 60 day clock.Did I screw myself by not depositing the check yet?  

Depending on the state you can't just buy a property and kick them out you generally have to wait till the lease expires.