How to change /project-view/ part of the post address?

You can change the custom post slugs for Projects, Galleries, Staff, Downloads, Testimonials and Parters posts.
Go to WP Admin > Live Composer > Settings > Post Types and change values in the next fields:

Make sure to visit permalinks section after making these changes!

After making changes to the custom post type slugs, you'll have to visit WP Admin > Settings > Permalinks page. No need to change anything, just open this page in your browser. This way WordPress will know that URL in the database should be updated.