I recently updated the slides used but when I launch the client it points to an older slide. I can not find the location of the slide to update that as well.
The Player downloads the new slide from the CMS.
Assuming you uploaded your new content via the CMS (and didn’t just replace files in the CMS library yourself) then the Player should pickup those changes the next time it connects.
Where do I find the upload point? This is on a standalone that has no network connectivity.
If your network is standalone, then you should have the Player and the CMS on the same network as each other, and the Player needs to be configured to connect to the CMS and download new content.
You would make the changes you want to your layouts in the CMS, and the Player will then show those changes. You can’t directly modify media items in layouts by replacing them on the filesystem - you must do it via the CMS web interface.