Contact the promisee to discuss your desire to cancel the promissory note. For example, you may have purchased an undeveloped lot in a planned subdivision by signing a promissory note with the developer. However, the developer never started the project and you no longer want the lot. Negotiate a settlement ending the financial responsibility. Get details in writing but consult with a consumer affairs attorney before making any payment.
Show the attorney the promissory note and the settlement. Confirm that the settlement will lead to cancellation of the promissory note pending cooperation from the promisee.
Write a "Cancellation of Promissory Note" letter or have the attorney write one for you. The note should include details of the original promissory note and also indicate that the original promissory note is canceled at the request of both parties. Have the promisee sign the document in the presence of a notary. Also have the promisee write "void" across the original promissory note and sign the document in front of the notary. Pay the promisee any money promised in the settlement.