Or "Help! I have to cut 5,000 words!"
Source Unknown - Anyone want to claim credit?
Look for scenes that develop the character but do little to develop the plot. Find a way to communicate that character trait more efficiently. Get right to the plot points.
Remove favorite phrases and extraneous modifiers (a little, kind of, very, just, sort of, etc.),
Remove unnecessary detail (perhaps a minor character description/ place description could be 2 sentences instead of 4),
Condense dialogue (removing repetitions, getting to the purpose of the conversation),
Remove unnecessary actions (if a character goes into the kitchen, maybe I don't need to specify that he first stood up and then walked into the kitchen),
Look for places where I repeated myself only a few sentences apart,
Cut places where I explained the obvious to the reader (show, don't tell)
Minimize transitions (like "was walking" could be "walked," which helps with passive voice).