First you will need to loosen the screws that hold the toggles in place to secure the removable roller.
Lift or roll out this bar. And set aside. This is roller #1.
mix these up. Set the bars so the double spaced needle holes are at the same end. If you have a machine that is double space all the way, try to keep the bars in the same order as they were in the machine.
|See what kind of 'black' you can get and all the bits of thread|