license renewal mgmt -- multiple allowed?

I've got a license that expires 12/31/17.

I've purchased a new license that'll replace it -- valid from 12/31/17 -> 12/31/18.

Can I upload/install the new license it now, without disabling the current license? I.e., will both licenses coexist, and simply rollover automatically on 12/31/17?

Or do I need to MANUALLY update -- removing the old, and installing the new -- on 12/31/17?