How to remove Div tag?

I agree with Rob, the hard part is usually finding the proper beginning and end tags. Either place the cursor as mentioned or select the entire area (if you can) and then go to code view to remove that portion of the design. Take note of what you remove and of course keep a backup in case you make a mistake.

The best way is usually to do it in code view, so you can be sure that you capture exactly the set of tags you wish to remove. Sometimes I start with design view, so I can place my cursor within the section I wish to change or remove, then switch to code view to do the work.