Remove any cushions that aren't attached or affixed to the furniture and set them aside. You can take the time to deal with these separately in the later steps, and it's crucial that the furniture is stripped down to its fabric base without any covers or cushions lying on top of it. This will clear the way to remove the rest of the fabric without any obstructions.
Carefully strip off all of the old material down to the bare frame. Use your utility knife to cut along the seams where the fabric is stitched, and take extra caution to make sure that you don't slip and cut your hand. Try your best to preserve the integrity of each panel of fabric because it will make measuring for the new ones much easier. Depending upon how large your piece of furniture is this may take quite some time, and if you encounter any staples you can use the needle nose pliers to remove them.
Take out all of the old padding and stuffing. Once you've removed all of the fabric you need to make sure to separate all of the old padding because it tends to get worn and flattened with time. If you are going through all of the work to reupholster your outdoor furniture it's important that you replace the padding material as well. Make sure to leave it intact so that you can duplicate the measurements for your new padding.
Separate the old fabric material into individual pieces. By doing this you will be able to take measurements of the old panels and also directly from the furniture itself to create your new fabric panels. Take your time measuring and make sure that you don't forget to include or skip any sections of the furniture.
Duplicate and transfer the measurements onto your new material. Working one section at a time, carefully outline your measurements on the new fabric making sure to be as accurate as possible. It's ok if there is a little extra fabric that can be tucked under a seam, but if you come up short you'll have to start over with a new fabric panel.
Snip out all of the fabric panels for your furniture and lay them out according to their order of installation. This will help you to be organized and avoid getting mixed up when you begin sewing them back onto the furniture.
Measure and cut out the new padding and stuffing pieces. After you've cut the new pieces, lay them down onto the furniture in position so that you can begin attaching the new fabric panels.
Sew in the largest panels first. The middle and back of most furniture usually represents the largest pieces and it's important to get these done first. This is because all of the small pieces depend upon these for reference lines and they will give you a good base to attach smaller supporting pieces.
Attach and sew in the small panels next. These will go in fairly easy if you've done the large panels properly, just make sure that you go slow and pay attention to detail because problems and mistakes with the smaller panels will be much more obvious.
Repeat the measuring and sewing process on the cushions and reinstall them on the furniture. You'll need to remove the panels and measure the padding in the same way, so just apply steps two through nine to the process of reupholstering the cushions. Once they are done simply place them back on the newly reupholstered furniture where they belong in order to complete the project.