One of the most common remarks from new users, is
" I have threaded my machine 100 (or more) times and cannot get it right." You really need to leave that attitude at the door and just keep practicing until you get it right.
If you follow a threading video and do it along with the video, starting and stopping and repeating as needed, over and over again for one sit-down session of it, you will learn to thread (and change thread colors) your serger easily.
On Youtube, type in your Brother Model name and threading.
I have taught thousands of people how to do it this way.
This enables you to use your serger without anxiety about threading.
How I thread my Brother 1034d Serger by Candice Ayala
How to Thread the Brother 1034d Serger (Sewing Report)
Threading Brother 924d/1034d Serger
Threading Brother M343d Serger
Lower Looper Brother M343D and1034DX
Brother Serger 1034DX
This Threading video for the 1034DX model was made by our member Moriah Leilani Rosario