O.T. Redirecting all files to new URL

I'd appreciate some help with this... I replaced 2 existing web sites with a new one. The file layout is not the same as it used to be so I need to redirect all requests files in the old web sites to the index.html of the new site. After reviewing the mod_rewrite users guide, I could not find any examples of how to do what is required inside of .htaccess I'm sure this is a simple fix, but I've got the customer breathing down my neck about it and I'd be grateful for a solution. Jack