Just to let you know, I was taught this quick way to do it - but I had never done it by myself, on my own - I had a vague memory how the different steps...
1. Snip the thread above the machine on all four spools - go on, don't worry it will be fine.
2. Replace your old thread with the new cones, and bring the new colour through the thread guide.
4. Pull the thread through gently - gently is the operative word here. I pulled my looper threads separately from the needle threads, but I don't think it matters - it is just easier.
5. For the left & right needle threads, don't pull the knots through the needle eyes (I couldn't). Snip the threads and re-thread both needles with the new colour.
6. Off you go - funky seams all the way!