how to delete a set of contacts?

Hallo.
My BB 9790 after repair came back with no contacts. Synced gmail. Contacts r now double, I.e. 2 sets of gmail contacts on SELECT CONTACT LIST. how do I delete the second set?

Then I had setup my yahoo also. Even without doing anything, the yahoo contacts also got synced. Now I have 3 of every contact. How do I delete the yahoo contacts?

thank you

Turn wifi and cell coverage off. Go into the settings, where you add email accounts, edit the email account and you'll see the sync settings. UNcheck sync contacts. Feel free to delete then.

Why turn wifi and cell coverage off? So you don't end up deleting from the server is something goes wrong.