The screws at the back are for collimation - don't touch
I'd say there's a ring that unthreads in front of the meniscus (front curved lens) allowing the meniscus to be removed. If so you could unthread the ring and use something like wooden icy pole sticks to get the meniscus out. Do it on a table with the scope on a few layers of towel and use cotton gloves to avoid getting finger prints on the optical surfaces should you inadvertently touch them. Use a pencil to mark the side of the meniscus and the tube so it goes back in in the correct rotational orientation.
It's good to get some practice in on stripping down scopes and you may as well start with a cheap optical tube like this one. You can find articles on the internet about disassembling Schmidt cassegrains that would be good to read to give you an idea of how to proceed.
That's my 2 cents, feel free to ignore