Page titles show in the hero at the top of each page, the page tab, and in the 'explore' sections.
Find the page you want to edit.
Hit the cog in the top right and select 'edit page'.
Across the top are a number of options, select 'Properties'.
In the 'type and title' section at the top, change your title.
Scroll to the bottom and hit save.
Site design by Elliot Parker.