Hi Elliott
to IceInSpace!
You can go to the Post Office and request a
Money Order, made out to "IceInSpace", for the amount ($33.00 for the book and calendar). You then pay the Post Office the $33.00 (+ some fee) in cash.
You then put the money order in an envelope, put a stamp on it, and send it to the address listed above.
I hope that helps.
Please PM me if it's still unclear.