Using straight connectors with screw endpoint?
those type of crimp connector are commonly known as bootlace ferrules. The red wire has got the same connector as the black, so just follow the way that has been connected. You may have to unscrew the cable clamp a fair way to be able to get the connector under the metal clamp plate, but once you've got it in and tightened securely they won't move.
Hope this is of help.