Help needed changing crown on Omega seamaster

Please. Can anyone help me. I have lost the crown on my omega seamaster but I am still able to adjust the time and date with some patience. Is it possible to add a new crown to my watch by myself or should I take it to the repair shop. I have looked on the internet to find the correct one with the right size but it's a jungle for me. Perhaps some of you could help me out. I will post some pictures of the watch. Thanks in advance. Kim from Denmark

I would probably do that. But was also interested in if it was possible to find a replace crown somewhere. Just a little bit difficult to find out what to buy

Thanks a lot for your reply. Difficult to change by myself or should I leave it to the watchmaker?