Looking for a low-cost Loan servicing software

Hi everyone,

Inherited an owner financed note on a residential property.  Around 7 years left and buyer is a bit of a headache (always late with partial payments etc.) Does anyone have any recommendations on low cost loan servicing softwares for mortgage payment collection as well as automated reminders etc.

Also open to selling the note - has anyone dealt with any of the note buyers out there? Thanks