Go to My Account > Subscriptions > Renew.
If you have the same billing address as last year: Under "Payment Details," you may already have your billing address saved from last year with "Pay Later" above it. Make sure the radio button next to that address is selected, and click "Renew." An invoice (with check/wire remittance information) will be emailed to you, and the pending order will also appear under My Account > Order History > Pending Payment (with a link to pay online by credit card later, if you prefer.)
If you have a new billing address: If you need to change your billing address, click the "+ Create Payment Method button" on the renewal pop-up. Enter your billing address as it needs to appear on the invoice, and under "Payment Method" on the right, select "Pay Later." Click "Save" at the bottom. The new "Pay Later" address will appear under "Payment Details." Make sure the radio button next to new address is selected, and click "Renew." An invoice (with check/wire remittance information) will be emailed to you, and the pending order will also appear under My Account > Order History > Pending Payment (with a link to pay online by credit card later, if you prefer.)