How do I delete these contacts?
Delete contacts
You can only delete your Hotmail or Outlook contacts from the People app. If you've connected other accounts like Google, or Skype, you'll need to go to that app or website to delete those contacts.
On Start, tap or click People.
In the search box, enter the name of the contact whose info you want to delete. You'll see a list of contacts as you type—tap or click the one you want.
Tap or click a contact.
Swipe in from the bottom edge to see the app commands. (If you're using a mouse, right-click within the app.)
Tap or click Delete.
Source People app help