How do I get plex to refresh artwork for an entire tv series

All of my media already has artwork and .nfo files from years of using XBMC/Kodi.
This of course I want to use. I have the XBMC importers setup for the agents.
I have a show that the episode thumbs were terrible so I made a screenshot from each one and replaced.
How do I get Plex to rescan a show and replace with all my new artwork?
I know I can do it individually but don’t want that hassle.
I selected the show and clicked refresh but that didn’t work.

Sure you did a real ‘Refresh’? Or did you click the ‘Circled Arrow Thingy’ that just jokes around and says it’s Refresh?

They are quite different, but it depends on what kind of mood Plex is in… once it get’s it’s paws on a bundle it takes an act of God to get it to let go, so let’s stop just short of The Plex Dance…

Travel to a TV Show library in Plexweb then in the upper right, under the ‘Gear’ select ‘Refresh All’… now it’s important to note that depending on how large this library is - it could take the rest of your life, but to my knowledge a real ‘Refresh’ (a complete re-investigation and reloading of material) is only really allowed at the Library level - for all the items in that library - and yes I know it defies logic.

… and it’s still quite possible that you’ll have to Plex Dance all the items you want to ‘Renew’ anyway…

I could be wrong.

Just dancing I guess.

I tried a different method real quick. I simply went to my NAS and moved the folder of the specific show.
Opened Plex and confirmed it was gone.
Put it back.
Same artwork… maybe Plex still had it in a database or something?

Let me confirm I’m even doing this correctly.
In the edit library options under advanced for Agent I have XBMCnfoTVimporter. Now with nfo in the title does it concern itself with ‘my’ artwork or just the nfo? What is the personal media shows listed under Agent?

Now different programs like different names for artwork.

In my root folder for each tv show I have artwork for the ‘poster’ under at least two names… ‘poster’ ‘folder’

For my season posters I have them as ‘seasonxx-poster’

And for my episode thumbnails I have them as ‘SxxExx - show-thumb’

Will Plex recognize all of this?
For the particular show I was testing I deleted the ‘thumb’ from the episode screenshots because I’m thinking that is what Plex is looking for.

I also have various other arts I use for XBMC like ‘clearart’ ‘logo’ ‘banner’ ‘extrathumbs’ and more but Plex is a little more boring with the artwork.

If you use the .nfo importer agent, then the filenames denoted in the .nfo file are used as artwork.
Nonetheless, if you swap the .nfo or the jpg files (which were originally used when you added the show into your library), then you need to Plex Dance the show. Otherwise not all info is imported freshly and remnants of the previous metadata or poster selection remain in the Plex database.

I thought the first ‘Plex Dance’ thing was a joke, lol.
It took about 6 tries but I finally got it.
Under Agents in the main settings page is where I made my last change so I had something wrong there.
All good now though.
Thank you both for the help.