Make sure to spread the foams a little before trying to put them on, it's unneccesarily hard to put them on without doing so.
Pick them up, take two opposite sides and pinch-pull them a little, keep doing that in a circle, this'll make htem a bit more spread out.
After that, take the monks, pinch-pull them and slide them over one side of the earbud, keep holding that one part of the foam on the earbud, and slide the other side across the whole earbud.
Shouldn't be too hard, took me a couple of seconds tops :>!