The steps are easy to understand but not so easy to do.
In addition to my usual chemical baths (some approved, some not,) I sharpened the end of a sewing needle so that it is like an oval faced chisel.
I use the tool to remove the green crystals one speck at a time.
To get the idea, spread some chunky peanut butter on a saltine cracker and remove it with a tooth pick.
Try not to touch the cracker with the tooth pick.