Lay out a plastic pallet on the floor as shown here. The plastic pallet can be made by cutting a large trash bag.
Lay the mattress layer of latex on the plastic pallet and fold the layer in half vertically. If the layer is split into two, then stack then on top of each other instead of folding them.
Roll the mattress into the plastic. This step is usually better accomplished by two people rather than one.
Use your body weight to keep pressure on the layer while rolling the latex so that it rolls as tightly as possible.
Once the mattress is tightly rolled, tape the plastic to prevent the mattress from unrolling. Put the weight of your body on the mattress layer while you tape; this will help to press the air out of the plastic.
Stand the rolled layer vertically, then roll the excess plastic up at the end and tape it shut. Flip the mattress layer and do this for the other side.
Take the rolled layer and insert it into the box that Sleep EZ sent. Make sure that the mattress layer is as far into the box as possible, to allow room for taping.
Tape the box together in a way that ensures that it will not come open in transit. Put your return label on the top of the box, and take to your local FedEx store or call your local FedEx hub for pickup.