That's the key to taking the dabs out, tap/knock them out, gently, don't try to pull them out towards you, as you'll cause damage to the screed you're setting up. Just give them a gentle tap to the left or right if put on horizontal, or tap them up or down if put on vertical. Taking them out this way doesn't cause the same damage around the wooden dabs/dots,, (I call them dots, but it's just the same). I've also put them on with a little cement in the mix to tighten them in quicker and corner beads too, but as Roy says, do it the right way when learning.