How to invoke Gnome on Ubuntu 14.10?

Sorry I am such a dummy but I wanted to change to the Gnome desktop instead of Unity and I have downloaded it-I do not know how to invoke or execute it. How do I bring it up ?Thank you in advance.
joe

joboy,
A quick search turned up the below link. Did you try searching yourself?

How to Install the Gnome Classic Desktop in Ubuntu 14.04

Yes-I am okay now, thank you .