The number one thing I would suggest is this:
Fix the whole post, not just one little problem amid dozens. It's been said by SO management repeatedly that edits should not be used for "turd-polishing" — such as putting markdown syntax on a URL while spelling, capitalization and grammar problems go uncorrected. (In fact, they've suggested that reviewers should reject turd-polishing edits.)
- Most Important: Fix spelling, capitalization/punctuation, grammar.
- Fix URLs (add markdown, fetch titles or work into the sentence)
- Add helpful formatting
If you do these three things, you certainly aren't in danger of "changing the meaning", and chances are high that you've cleaned it up to the point that the writing doesn't need to be changed at all.
At that point, if it's still bad, go ahead and try to rewrite it a little bit. But, separate this edit so that it can be isolated/rolled back to a still-improved version.