Carefully choose the ironing settings: it should be preheated to the hottest temperature the material can handle, but without a steam. Press the iron down over the patch for about 15 seconds, then peel the patch from the base material. It is better to use some gloves/pliers because the material and the patch can be very hot. Detailed instructions on removing patches you can find here
Here are few types you can follow to remove iron-on patches:
. Heat the patch:
Use a heat source, such as an iron or a hairdryer, to gently heat the patch. This will help to loosen the adhesive that holds the patch in place.
. Scrape the patch:
Use a butter knife or a similar tool to gently scrape the patch off of the fabric. Be careful not to damage the fabric not to damage the fabric as you scrape.
. Wash the fabric:
Once the patch has been removed, wash the fabric according to the care instructions to remove any remaining adhesive or residue.