in most cases it is embroidered directly onto the towel..I'm not sure which one you are referring to though..there are some available on other websites that are stitched separately but those are the ones that do not have the hole in them for hanging..

most designs come with instructions.

here are some free instruction packs with pictures.If you mean a toweltopper like this. take a look.

When you click on the link I added, you will find a free instruction to download and ohow this is done.
Good luck and lots of succes