I thought it was the Featured Pages slider you had questions about. Is it the Featured Page widget?
You should be able to use the manual “Excerpt” box when editing a page for that. If you don’t see it, click the “Screen Options” tab at the top-right and check off the option. Any text/HTML you enter there should replace the default excerpt.
If I’m misunderstanding what you’d like to do, please clarify. Thanks.