Course of action with this tenant

[Franklyn Ventura]

I have a tenant who pays $965 as agreed on our lease. I agreed to lower the monthly payment to $900 (informally) in exchange for the tenant to take care of the landscaping and cleaning of the exterior of the house.

The tenant stopped almost immediately and is no longer doing anything. Tomorrow there is a snow storm and I am contemplating wether I should try to have the tenant plow the snow, or how I should move forward with making the monthly payment $965 again, and simply hiring someone else for the job. Any advice would be greatly appreciated.