htaccess File

I am working on doing a page for page 301 redirect. CS Cart is my existing site and I am migrating to word press on another server. Old site is and new site is I don’t want to lose SEO work So under templates I found htaccess file. When I open it I see Is that where, line by line, I put old page to new page. If that is all there is to it where is the htaccess page residing and after I edit the page do I just ftp and overwrite the exiting one. I had trouble finding the htaccess page on the site but yet it shows up under my skin as a link.

Thanks for any help,

Howard v