It's the biggest hassle in worm farming. There are hundreds of former posts on here about how to separate worms from vermicompost.

I have a Worm Factory, so the accepted method is to harvest the oldest tray after about 3 months, give or take. The oldest tray will be the one on the bottom, so it is necessary to move and then re-stack the other trays and then put the oldest tray on the top. From there, leave the lid off with a light on over the bin, and gradually brush off the castings from the top layer bit by bit and put in a separate container. As you do this, the worms will drill down away from the light and eventually go down through the perforated bottom of the tray into the bedding on the newest tray. That's how it works in theory.

The marketing of these multi-tray systems says that the worms will move on their own out of the oldest tray, but multiple worm herders have experienced the unwillingness of many worm tenants to leave their current housing. The other factor that you don't really realize until you are elbow deep in worm castings is that freshly harvested vermicompost is HEAVY and gluey and wet, and that it is full of tiny worms that are almost impossible to extract from the gluey lumps. The idea that you can "brush" the layers of VC off is really comical at first, like brushing off peanut butter.

I think it will work better next time if I allow more time for each step. After the initial pass when most of the larger worms have been shoo'ed down out of the tray, I will put the vermicompost into a separate plastic bucket and just leave it for a while, to allow baby worms to hatch and grow up a bit and the VC to dry out some more. As it gets dryer, it gets to the point where it crumbles into small round particles and it finally becomes more realistic to "brush" layers of it off. If you do this under a bright light you eventually wind up with a ball o'worms at the bottom and you can plop those back in the bin. It might be necessary after that to set aside the VC yet again to make really, really sure the baby worms have all hatched and then do another round of extraction.

One dreams of a worm sorting trommel, just a small countertop size...

I'm new to this as well. Since I don't plan to use the vermicompost until next year, I'm taking my time. I started a second bin and transferred as many worms as I could find to the bin. In bin #1 I added a bit of food, not as much as usual, and once a week I'll fish out any worms I find and move them to bin #2. Poking around the bin, I see a lot of eggs and tiny baby worms. My plan is to let as many eggs hatch and allow the baby worms grow large enough for me to pick out. I'm in no rush and over time I will add less food and let the existing worms finish off whatever food and paper is left in the compost which I'll store until use. Again I'm in no rush and I sort of find picking out the worms relaxing.

Btw I've noticed that the eggs float. I accidentally flicked a bit of compost into a small container of water and I noticed the eggs floated to the surface and were easy to differentiate from the actual compost.

I have been vermicomposting for about 5 years and only this year started to regularly use worm casting to fertilize the vegetable garden. Trying to sort worms from casting is nearly impossible. What works for me is wait until the bin gets over 12 inches deep, the bottom half will be almost worm free. You make another bin of the same size, transfer the top half of the bin(where most worms are) to the new bin. Place the new bin on top of the old so that the bottom is in direct contact with the finished worm casting. What happens is the few worms left in the finished compost will come to the top, just under the bottom of the new bin. They come up because of the liquid coming down from the top bin. For a few days, you lift the new bin away and pick the worms off the top of the finished compost once a day. After that, the compost will be worm free. You should keep the setup together like that until the worm casting in the bottom bin is used up because you do NOT ever want the worm casting to completely dry up. It will be as hard as a hard clay. Ask me how I know :-)

I have been worm composting for about 20 years. I have tried many methods. The easiest is to put the compost you want the worms out of in a wire sieve and place it over where the worms are to go. Put in sunlight and they will all go downhill quickly. There are other methods that I use but this is the quickest. If you want to collect babies, put some of their favorites into a window screen holder and bury where the babies are. They move right in!! However if they are eggs, it takes 3 weeks to hatch.