Change all http:// to https:// so that my SSL cert shows as a green lock in the Chrome URL bar

I recently installed an SSL Certificate on my website put the pages are not showing as secure because some of the links on the pages (and images) are http:// instead of https:// I need everything switched to https:// so that the green lock shows in the menu bar (see attached file). Please only bid on this job if you completed this task before, and please let me know how we will make the changes. Please message me if you have any questions. Thank you!