Hello,
Don’t worry about that, you did most of works in right. Just need to change the format of the item’s link to follow this: your_domain + #section_id
Eg:
Your site is: http://website.com
Section ID is: section-services
Your menu link will be: http://website.com/#section-services
This is a screenshot: http://i.imgur.com/7oYwze1.png
