Originally Posted by Ragnarok

Leave the old UA card alone for now.

Then apply for the UA Explorer Card with the 60K bonus now, ( first year annual fee is waived.)

( Do not cancel your CO card first, as you might need to allocate credit line from it to your new MP Explorer card )

Then cancel your CO card before annual fee is due again in June.

Cancel your new MP Explorer card before annual fee is due in Jan 2013.

Then finally, convert your old UA card to MP Explorer ( if Chase haven't yet at this point convert it automatically ).