If the web site is not live, you can backup the existing web site contents and you can delete all contents. Once you take backup, install WordPress to design a new layout.
If it is live web site, install WordPress in subfolder and complete your web site design. Once you complete it, you can simply change your URL to your main site. You can refer following codex article to move your wordpress to root directory:
http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory
Thread Starter
vfcox
(@vfcox)
I am ok with how to do it, but I am wondering if I should or do I need to delete the other page files on my host for a successful WordPress installation. For example, I have 4 pages in addition to my index page. Will there be a problem leaving those live or should they be deleted after the new site is up and running?
Thanks again!
If the file names do not conflict with WordPress files then there is no issue to keep them.