Doctor sent me a perscription for flector patch (diclofenac). I don't know how to use it?

Ask doc or pharmacy. Flector patch (diclofenac) is a topical non steroidal anti inflammatory drug. It is applied to the affected area over unbroken skin. If your doc has written a prescription, that information is on the prescription. The pharmacist also knows how to use the patch and there is product literature on - line and in the box of patches.