Property Manager - ceasing service

Tenants are being served notice for not paying rent, agent has given termination notice, but I no longer want a tenant in there and start doing my own renovations (old run down house), I got in an agreement with them 1 year ago:

1. Do I need to give notice to PM to say I don't need a new tenant so don't need the PM service anymore?

2. It has been 1 year, does the 90 day notice apply? What does it apply to?

3. I also notice changing agents doesn't require this notice either? Whats the go with that?

If anyone has come across this issue that don't need agent anymore, I'm just scared they know I'm leaving so they don't chase up with terminating the unpaying renter.
If the place is vacant you don't need to give notice to your current property manager.
You can list the property yourself or you can sign a new agreement with a new PM
Tenants are in arrears - but lease still holds.
Your pm agreement stil holds and you cannot re- lease the property either yourself or with another agent during a fixed term agency unless its by mutual agreement.

You can renovate if you get vacant possession.