......
@legsroses Did you reinsert the pistons that came out and clamp them (or wedge with a block of wood) to prevent those from coming out again? The stuck ones will then be forced out with air or grease. If one or more is out you won't get any pressure building to remove the stuck ones.
I would not trust thick gloves using air! Those pistons come out amazing fast and hard and can easily crush or remove a finger. I put thin blocks of wood (about the thickness of one and a half or two brake pads) and
wrap the cylinder in a heavy towel- then apply air with caution. If you do it right they'll stop on the wood and be out far enough to then pull them out by hand.
Grease is the safer method that
@Gregger mentioned.