audio tracks from mono to stereo in a sequence-avid

I want to turn the 2 mono tracks of clips in a sequence in to 1 stereo track I know how that works in a bin but now I want to do that with clips that are already in a timeline

I found a post about that http://community.avid.com/forums/t/106804.aspx.  and I don't the answer: +1

anybody who help me out

Thanks

Core