You may recall that I was asked to reduce a book from 82,000 words to less than 70,000. I have to say that I've enjoyed that daunting task, and I may have improved the book overall.
When you cut, you have to look at what the least useful parts of a story are. What I found was a subplot that stretched credulity somewhat. It made a satisfying little "ta-da" at the end, but now that I've cut it, I think the book is stronger, more believable.
The bad part is all the little references that must be found and changed or eliminated. Four people in a group becomes three. A two-day period becomes one. Time and adjectives must adjust. I'm halfway through that part, after which I'll ask a reader to check for continuity.
Then I may look at some of the others and see if they could benefit from some cutting.