- Open the advanced configuration manager by typing about:config in the address bar and pressing the enter key.
- In the configuration manager, find the preference browser.download.useToolkitUI and set this to false
- Restart Pale Moon (completely exit and start it again)
- Right-click a toolbar button (e.g. the home button) and select "customize..."
- In the customization panel, find the Arrow icon "downloads" and drag this into the navigation bar to your desired spot (e.g. to the right of the search box)
Note: if you omit steps 4 and 5, the panel for downloads will be positioned in a strange or arbitrary location as it's tied to the location of the button that's not present yet in the UI.