It is as easy as ABC to delete one or two contacts from iPhone: touch Contacts app or Phone app on your iPhone > touch the contact that you want to delete > touch Edit on the top right corner > scroll down the window and you will see Delete Contact. Just click it and then pop up “Delete Contact” and “Cancel”. Directly tap “Delete Contact” and the contact disappears in Contact app.
If you want to batch delete contacts from iphone, you may need this guide:
The Best Way to Delete Contacts from iPhone in Batch
With it, you can remove multiple contacts from iPhone's memory, Exchange, iCloud, Yahoo!, etc at once.
Someone here at Android Central very probably knows that, but you may be better served by the iPhone forums.
