Ladies, I use to work in a garment factory and sewed on a serger, and I own one now.The loopers are a bit harder to thread but if you have a pair of long tweezers it makes the job a lot easier.My serger has dots painted on the places where the thread goes.
Also for those who have trouble changing the thread, tie on, losen the tension and pull through until you have the color in hand ( you will have to break the thread near the needles, they will pull through but not very easy and you can break the needle) when all is re-threaded just reset tension.Always do a practice sew first.