Open Settings → Navigation. The left column contains shortcuts currently in your header and the right column contains available shortcuts.
You can drag a shortcut up or down to reorder it. You can also drag a shortcut from In your header to Available shortcuts to remove it, or drag it back to the left to add it again. The whole destination panel is a drop target, including the blank space below its shortcuts. The Add, Remove and arrow buttons remain available as an alternative.
Rubbish Bin is included in the default desktop shortcut layout and is always available from the mobile menu. You can remove or restore the desktop shortcut from Navigation settings.
Settings can be reordered but cannot be removed from the header.