I’m looking to buy a duplex and house hack. The duplex I’m interested in is currently occupied in both units. One tenant is paying month to month, the other has a lease that ends in April 2020. Can I buy the home as a primary residence, and “kick” the tenants out who are paying month to month? With a reasonable time for them to move of course. 

It will depend on what their lease says, but most month-to-month leases will have something like a 30 or 60 day notice required if either party decides to not continue the month to month rental agreement. It should be really straight forward to not renew their month to month agreement. 

Most lenders will be okay with that as long as you can show that you legitimately do intend to move into the home within a reasonable amount of time. 

As part of your offer you may ask if the current property manager will give the notice so that you can get into the home earlier.  They may not be willing to do that, but it's at least worth asking.