Why are the sentences in your piece of writing in the order that they’re in? Why are the paragraphs in the order that they are in?
Step 1: Print out your piece of writing, get a pair of scissors, and cut it up by paragraph. Rearrange the paragraphs and see what happens. Play around. Cut it up by sentence if you want and try rearranging the sentences.
Step 2: Type up the new version exactly as it’s been rearranged, even if it has gaps and doesn’t make sense.
Step 3: Fix the new version so that it is a coherent piece of writing.