It sounds like this seller got incredibly lucky with the first lien that fell off and was not renewed.

I would like to notify a tenant of a rent increase and rental renew for another 12-month lease. 

Generally either 30 day or 60 day notice of non renewal depending on lease and local laws.

You just have to choose and inform one of the tenants they need to move in accordance with their lease (60  days notice of non-renewal usually). 

Taxes just increased very high I use to pay 2200 for mortgage and now I am paying 2500 , Iam not really sure if I’m able to push their rent any higher. 3rd floors lease is up for renewal and 2nd floor just moved in 5 months ago .

As far as the renewals, yes, you can get residuals on renewals and after a good 5-10 years, if you have a big enough book you can pretty much live on those residuals.

It is called 'notice of non renewal'.

I like this style for the following reasons:1) I require a parental guarantee - no payment issues2) I sign one year leases - I start inquiring to my students in February to see if they will renew (100% renewal for those not graduating so far) which keeps my vacancy rate at 0.3) I require a group of students to rent the house. 

@Peter Lohmann"In spite of the softening, the market remains, and likely will remain, a healthy region for multifamily development.Ohio State is a large and endlessly renewable renter pool, and it anchors the market’s economy, providing a level of stability uncommon to the Great Lakes Region.

However, if you're a month out, it's probably time to send a notice to the tenant advising whether or not you will be renewing the lease and at what price.