Go to the magazine's website and click on "Contact Info" or "Contact Us" to obtain the physical address of the magazine. If you are in possession of a copy of the magazine, flip through the first few pages to find the masthead, which will include the phone numbers, addresses and other information.
Write down the back issues of the magazine that you want. If you already have the issue of the magazine you want more copies of, look at the spine and write down the volume and issue number. If you're unsure of the back issue number, go to the website's archived magazines to find it. Or call the magazine's customer service phone number.
Fill out any necessary forms that some magazines require when you are requesting back issues. Often these can be found toward the back of the magazine.
Compose a letter requesting exactly which magazine name you would like, the amount of back-ordered copies and the exact volume and issue number. Some news magazines require that you specify the exact date of the magazine.
Write the letter as you would to a business correspondent. Include a salutation like "To the Department of Back Issues" and end with a salutation like "Sincerely, John Doe." Type it in proper letter form, with correct punctuation and grammar.
Print the letter out and put it in an envelope with the correct address on it. Also include a return address.
Include a check or money order with the letter. If you're unsure as to how much the back orders will cost or who to make the check out to, call the customer service phone number of the magazine. Do not send cash.