Rewrite and revise. Do not be afraid to seize what you have and cut it to ribbons ... Good writing means good revising.
Vigorous writing is concise.
Remember, it is no sign of weakness or defeat that your manuscript ends up in need of major surgery. This is a common occurrence in all writing, and among the best writers.
A drawing should have no unnecessary lines and a machine no unnecessary parts.
Instead of announcing what you are about to tell is interesting, make it so.
A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts.