Identify the area to stick. Make sure the area is clean and dry. Peel away the white sticker backing behind the patch. Be sure to peel only the sticker paper and not the embroidery patch. Stick it on the desired area, applying pressure with your hands. To maximise connection, you can either leave a paperweight on it overnight or apply heat with a hairdryer over the area for about 10 secs.
If the surface you are sticking on is not smooth, flat or rigid, you can use e8000 glue to stick the patches permanently on. Purchase it here.