Right now, I am number one for a number of terms in Google for one of my sites. I want to re-word the index that's number one..will me doing that affect my rank in Google? I'll of course leave my meta keywords, etc, etc. the same, and my <h1> the same. Thanks.
minor change or partial rewriting should not impact on your ranking. once you make the changes, make sure to do some link building for a while. if you are actively building backlinks, then continue doing so and you should be fine
If the current page is driving some decent traffic and you are ranking #1 for several terms, I would be hesitant to change much with it. If you want to target different key phrases I would probably choose to create a new page to target those different key phrases. Of course, if the current key phrases ranking #1 are not driving much traffic then the decision can be easier to make.
If you're doing a minor rewrite or small tweaks you will be fine as long as you don't accidentally mess up your keywords.
A change in the title, h1 tags may impact the positioning of your website. However, updating the content to reflect the latest information might not affect the position of your keywords. It is always good to update the content regularly apart from making any drastic changes in the page structure.