How to remove crown?
I've looked at the image you posted, and I think it's a Ronda 515 movement or something very close.
If that's the case, do the following.
Push the crown fully back to it's normal running position. If it's a screw-down crown then ensure it's unscrewed. Using the tip of a fine pair of tweezers (or similar - perhaps a needle) press lightly on the small depression that you can see in your photo (on the main metal plate of the movement, to the right, just below where the stem enters the mechanism). While pressing on that, gently pull on the crown. If it doesn't release, press a little harder on the depression but please be moderate with the force you use - if you press too hard you may damage the mechanism.
If you take enough care, you should be able to remove the crown and stem.
To replace it, make sure the movement is correctly aligned in the case and gently press in the stem. If you feel any resistance, then rotate the crown slightly and try again. Again, if you try and force it, you may damage the movement.
It is usually not necessary to place any pressure on the depression to reinsert the stem, but if all else fails it won't do any harm.
Please let me know how you get on.
on Oct 22, 2017