Not everyone sticks with the same email address forever — even though the Apple ID system was seemingly built with that idea in mind. Luckily, if you happened to sign up for an Apple ID using a non-Apple—as in not @mac.com or @me.com—address, switching your Apple ID to a new email address is easier than you might think. To do so, simply visit the My Apple ID page and then click on Manage your account. Once logged in with your current…