Here's the best way I found to work: Sit on the floor, get a big card/sheet of paper (A2 size or smt?) and put in front of you, and take out the mimosa pieces from your bag, bend each piece a few times so that you can 'peel' it in thinner layers, and put the peels on the sheet. Then once you're done peeling into thinner layers, get some scissors and cut the longer thin layers you made into smaller thin squares. Then you can just blend them in any normal blender (coffee grinder can work fine but depending on size, it will only break a very small quantity at once).
After each run in the blender, let it stand for a minute for flying dust to settle some, and then take out the top of the blender and put into a bag quick (purple pink dust will be suspended in the air, try to avoid breathing that).
If you dont peel the mimosa into thinner layers, they might break your blender, and if you dont cut up the layers into smaller squares, as it breaks down, the long fibers wrap around the blade and hold it, possibly over-heating/breaking your blender. But yeah definitely recommend powdering as much as possible (dont have to be absolutely thorough, as its nearly impossible with a blender to be 100%, just as much as you can), otherwise yield when extracting will be much worse.
Good luck