1. Click “Edit page” on the bottom left side of the page (use this page for example, it doesn't matter)
2. Click on the button with the picture, the media manager will now popup
3. If there are already screenshots for this driver, select the namespace on the left side. In our example this would be “mess → drivers → at → at486”. If there are no pictures yet, select the parent driver “mess → drivers → at”.
4. If there are no previous screenshots, add your image and enter the namespace name in front of the editbox with “Upload as:” in front, in our example this would be “at486:<image filename>”.
5. Upload your screenshot
6. Close the media manager and leave the page editing mode
7. If your new screenshots don't show, add ?purge=true to the URL of the page to refresh the cache

Please upload only screenshots that were created with MESS and the driver you want to upload the picture to.