How do you get an inherited tenant to sign a new lease?

[Christopher Stanis]

Hello BP Community!

What steps would you take to get inherited tenants to sign on to a new lease? 

My brother and I recently purchased a mobile home park in Williamsport PA. Most of our tenants have met with our management team and signed our leases. We have several tenants owning their own mobile home that have refused to sign a new lease. They are up to date on rent. However, the previous owner's lease could be fit onto a napkin, and includes very little of the legal protections important to us in a lease. 

What steps would you take to get tenants owning their own home to sign a new lease? Is threatening a 30 day notice too extreme? Thanks BP!