Hello Iron -
Please note that when you use Add Images on a listing that is eligible for revision on eBay, the images are not typically added to the body of the listing, they usually show at the bottom of the listing - outside of the template if you are using one. If you have attempted to do this on a listing that is eligible for revision on eBay and encountered difficulty, I suggest you file a support case with us letting us know exactly what has occurred - please be sure to specify the listing you have attempted to modify and we'll be happy to take a look.
It is unclear which portion of the other option provided you may be encountering difficulty with - you would just need to add your additional images to the Saved version of the listing you are modifying and then save it again. After you have saved it with the new images, you can then use the steps presented in the prior post to modify the active listing on eBay. If you are having difficulty with this or have questions, please feel free to let us know in a support case so we can further assist you.
- Craig