Remove "Leave a Reply" and "Be the first to comment" on twenty twelve

I’m at a loss. Seems there are “Leave a Reply” invitations all over my posts one at the top, two at the bottom. I can’t figure how to reduce the number of “Leave a Reply” invitations. I don’t really need one invitation at the top and bottom of my posts.

At the very least, I want to change “Leave a Reply” to “Your thoughts welcome.” Or something like that.

Also, I want to remove the “Be the first to comment” invitation.

I tried to override the twenty twelve comments section with WP Discuz, but the form doesn’t show up.

I checked Settings/Discussion, enabled “Discussions” on my posts’ visible window, and checked “Allow Comments” on my posts.

And, once “Leave a Reply” showed up on my posts, I lost the social links generated through admin panel “Settings.”

I’m using WP twenty twelve. I am using a child CSS, but have not copied or altered the comment.php file or the content.php file.

granniegeek.com

Thanks for your help!
Linda