How can one change the lock here?

Hello,

I have a door handle with a lock in the basement. The key can only be inserted from the outside. I want to replace the lock with another cylinder that can also be locked from the inside.
My question: Can I remove the lock as usual by unscrewing the side screw and pulling out the cylinder?
And can I then install a lock that I can lock from the inside?
Or is that not possible because the inside area is covered? I intend to install a Nuki digital lock there. A key should then be inserted inside and turned.

What speaks against it? Okay, at most, that you probably only mean the "Schließzylinder" and not the "Schloss," right?

You just have to check - I don't know if the NUKI 1/2 even still exists...

Yes, of course I only mean the cylinder lock. So far, mine have always looked different. Is it correct that I only unscrew the one side screw and then can pull out the cylinder lock with the key?

Yes, simply screw out the screw, insert the key, and measure. A cylinder always has two measurements. For example, 60mm left and 40mm right. Or 50/80, etc. There are double-sided cylinders and even the option to leave the key inside "if there is space" and still unlock from the outside.