First step, go into your Active Selling page and find the listing you want to fix. Right click on the listing and choose "Open link in New Tab" This will give you one tab with your Active Listings, and one tab with the listing you want to fix.
Once you have your item open in a new tab, go to that tab, right click on Revise Your Item (or Sell Similar - whichever you are doing), and then click on Open Link In New Tab. Now you should have 3 tabs: all your active listings, the listing you are fixing, and the Revise or Sell Your Item tab.
Go into the newest tab (Revise/Sell Your Item). Scroll down to the item description section and click on the HTML tab.
Right click inside the box with all the HTML coding and choose "Select All". Then delete it.
Next, click on the Standard Tab.
Now go back one tab to the original listing. Scroll down to the Item Description section. Highlight your text and copy it.
Go back to your Revise/Sell Your Item tab. Right click in the empty item description box (Standard tab!) and choose Paste.
This will paste your description content. You will probably have to fix some formatting, text size, color, etc... Once you have it how you like it, go ahead and continue with your listing and click on Submit at the end.
**VERY IMPORTANT** If you are doing a Sell Similar, don't forget to end your original listing!! If you leave the original and the new one up, you may get caught with Duplicate Listings, which will earn you a policy violation. In fact, it's a good idea to end the listing as soon as you have opened it in a new tab.
**ALSO VERY IMPORTANT** If your SSB listing is kind of old, from before SSB started offering the picture pack, you may need to save your pictures from your listing onto your computer, and then re-upload them into your Revise/Sell Your Item listing.
If you open the photo in your SSB listing, you will not be able to right click on it to save it. You will have to get a screenshot. To do that in Windows, open the photo and press the "Print Screen" button on your keyboard. Then paste that photo into a new Paint document, crop it, and save it. Do that for all the photos in your listing. Then when you go to fix the listing, you can re-upload those pictures. Once you delete the HTML coding, the pictures that you have in your listing body will be gone, so this is important.
With your newer SSB listings, you won't have to do this step. Just make sure that all of your photos are showing up on your eBay Revise/Sell Your Item screen in the photo section. As long as they are all there, you won't need to do the screen shots.
I hope this made some sense. If anyone has anymore questions about how or why I have been doing this, please feel free to comment or email me directly and I will help you out the best I can.