In reply to If you could tell me how to by tlbetts
If you haven't done this before, I recommend taking it to a watchmaker. This is a snap back, and the movement will need to be released form the back once the bezel and back are separated. The movt is easily damaged by attempts to pry it out.
I don't see a date code on your case back, so the movt itself will carry a code. If you click on 'Information' at the top of this page, you will see 'Date Codes' explained there.
If possible, ask your watchmaker or jeweller if you can take a picture of the movement to complete the record here. To find a watchmaker near you, go to the NAWCC website and there will be listings of member watchmakers by location. (National Association of Watch and Clock Collectors)