Changing Page Permalinks

I’m trying to change the permalinks for my pages, but it’s not working and I’m hoping someone here can help. An example of one page is my portfolio page; right now the permalink is set to “www.MyBlogName.com/portfolio-3.” I think the 3 may be there because it took me a while to get my site going and I created multiple pages with the name “Portfolio” before I got it set up the way I wanted.

A number of my pages have numbers at the end of the link that I’d like to remove. I’ve tried to edit them right under the page titles where it says “edit this part of the permalink,” but every time I do and click “OK,” it just reverts right back to the URL with the number. I know it’s not a big deal but I’d like to get rid of them if I can, I think it looks a little amateurish as-is. Any help you can provide would be very welcome.

Thanks!