What aspect of section 8 are you worried about? If you want to keep your tenants, you can take Shaw's advice below and just sign up with the housing people. Section 8 is the owner's choice. If you want to get rid of your section 8 tenants, I believe you just call up section 8 and tell them you don't want to have section 8 units and they take their vouchers elsewhere.
Hi, you can speak to the tenants and ask them for the phone number of their case worker or section 8 office, you'll need to talk to their case worker or someone in section 8 office so they could forward you the rent for the time. If you want to keep them as a tenant then you might need to sign a lease contract with section 8. Good luck.