How do I update an enrollment contract after adjusting signature requirements?

When an enrollment contract was initially configured to have all signatures required and now only one signature is required after one parent already signed the contract, the only way to correct this is to run the "Reset Contract Data" procedure from the action menu of the Enrollment Detail Screen. 

If you do not want to ask the parents to sign the contract again, you can manually mark the Contract checklist item complete but the "Contract Status" field will still be set to "In-Progress" and the student will still appear in the "Contracts Awaiting Signatures" query.