From the Contacts tab, tap the contact to be edited.
Tap the Edit icon (located in the upper-right).
If presented, tap the preferred account (e.g., Google, etc.).
Enter any of following info then tap Save (located in the upper-right).
To change the account type, tap the Dropdown menu then tap the desired account (e.g., Google, Tablet, etc.).
Depending upon the account type, the options presented may vary.