You'll need a pincer tool, a metallic kitchen whisk (thanks to HBB for this one) and both of your hands.
Step 1: Remove central metallic holder
Step 2: Fold first "petal"
Step 3: Fold rest of petals save one
Step 4: Tweak stabilizer
Make sure the stabilizer touches the wall all the way. You can make it more "round" for more stability