Once you have right clicked and saved it to a destination folder, you need to go to the torishop (at the top of the forums there is a button), click on textures, and upload it to the head texture space.
Remember you willl need to buy a head texture placement first though, these can be bought in the torishop as well.
Note: It is frowned upon to double post, please use the edit button in the corner of your post next time you want to add sometghing.