You do not need to return the whole order. When you are initiating the return, you can choose which items from your order you want to return. You can only make one return per order, so please ensure that you send back all of the items you don't want in one return.
If you ordered items that were featured in a bundle offer, you cannot send part of the bundle offer back. For example, if you ordered a phone that came with an accessory for free or at a discounted price, you cannot return just the phone — you must send the accessory back as well.