Open Email in Account settings, on the website or in the app, and enter the new address. Confirm it is you with your current password, or with a code sent to your current address if the account has no password. If two-factor authentication is on, you also enter a code from your authenticator app.
A link is sent to the new address, and your email only changes when that link is opened. Your old address is then told, with a link to undo the change for 7 days. Undoing restores the old address, signs the account out everywhere and removes its password, for the case where you did not make the change.
Google, Apple and LinkedIn sign-in keep working, and receipts for teams you own go to the new address.