Change the name. Any other solution is foolish and short-sighted. A terrible name is something that is haunt you for the rest of your time at the company. Just

Change the name. Any other solution is foolish and short-sighted. A terrible name is something that is haunt you for the rest of your time at the company. Just have the page links properly managed so that they mention the new name and the old name. In 6 months, no one will care or remember the old name. Internally, you can refer to it as the old name, and you can keep the filenames as is. It's a pain but that probably isn't worth the effort to migrate.