Look hun all you have to do is find the image you want in your signature and save it into your computer. To do this you right click the picture and select the "save as" option. Then you go to tinypic.com and follow these steps that Oreo gave you:
Uploading images from your laptop/files..using Tinypic
**And after that return to your post/signature and paste it there.
hope this made sense
Copy that Image code shown in the pic and return to this site click profile them forum information and paste that image code in your signature box. To paste you right click in the signature box and select paste. After that you save it and it should appear in your signature.