Here's a good article on when it can be done, and how: https://www.nytimes.com/interactive/2023/03/11/upshot/office...
(archive: https://archive.ph/gQiQW but it's not as easy to read)
Takeway: old skyscrapers are easier to convert than new ones, because they tended toward home-like small offices.
A modern skyscraper had to have a hole punched in it.