2 minutes on high (depending on the microwave - keep an eye while it’s cooking; you don’t want it to boil too much, it can ruin the substrate)
check the color of one of the feathers; if it’s what you want (it’ll lighten up when dry), rinse everything off in a strainer under cold water
lay everything out to dry
ready to go
I’ve also used a hot plate, coffee carafe and candy thermometer; they work well when you want to keep the dye at a constant temp for an extended time - stuff like deer hair, calf tail, etc. usually take a bit longer.