Permalinks…..how do I make the switch? old-site/new-site

Using WordPress 3.4.2 Theme is Pagelines lite

Hello all you wonderful helpful wordpress friends, This is my first wordpress site, learning so much, thanks to all of you..

Original site: lasvegasinfocenter.com (created in Frontpage)
New WordPress site: lasvegasinfocenter.com/mw.lasvegasinfocenter.com (placed in a subfolder during the learning curve/re-creation, the ‘mw’ stands for ‘my wordpress’)

I am almost ready to replace the original site with the wordpress site, but I am worried that something will go wrong, since I am not exactly sure how to do it.

Here are my questions:
1. Do I simply change the permalinks in the WP settings? New site will overwrite old site?
2. Or do I go to the folders on the server and move them around there?
3. Or, (if both of those are wrong), how do I do it?

Thank you so much for your help.

Kathy