Contact your lender to get the exact payment you need to make to pay of the mortgage. This may differ from the monthly amount on your loan statement so ask for the figure in writing to avoid confusion.
Write the check for the full payoff amount. Since mortgage interest accrues daily, estimate and include any interest that will accrue from the date you receive the final payoff amount to the date the lender receives the check. Opt for a high estimate to ensure you pay enough. Your lender will send you a refund check for any overpayment.
Contact you lender to determine if it will record the release of the deed of trust or if you have to do it yourself. If you are responsible for recording the release, get the paperwork from your lender and send it within the time frame your local government requires or you may face fines.