Stem conversion to threadless

looking for some knowledge advice. How difficult is it to convert a stem like in the image to a threadless setup?

The bike in the image is from 2010. Would it be safe to say its got .a 1" quill stem type dimension?

stemp

Do i just need one of these?

Yes and yes. The quill adaptor will work fine. The only potential difficulty is that the old quill stem has corroded in there and will be impossible to remove.