I'm not an expert in this in any way (I learn by trial and error!), but if you just deleted the article from the issue (e.g. from the Table of Contents, perhaps), I believe you can re-upload the article because the content (e.g. metadata, reviews, etc) will still exist in the archives. My suggestion is the following:
1. Use the Editor role, and select 'Archives'.
2. Find the article that you deleted (all the articles you have published or processed should be listed). Clicking on the article in archives should let you access all the normal pages associated with processing an article (i.e. the Summary, Review, Editing, etc pages).
3. Go to the Editing page and upload the article again (to Galley Proofs, I believe) and re-assign it to the Volume/Issue that you want, as you normally would have when you originally published the article.
Hopefully this works. I have gone through this process when I uploaded and published an article, and then realized there was a (minor) typo. I deleted it,and then replaced the original article with a cleaned-up version.
(Journal Manager, Ideas in Ecology and Evolution).