You didn't post why you think you the fish you are trying to replace died. If you suspect aggression from the remaining tang, then I would think adding another yellow with your existing would be close to impossible. Some people have had luck on occasion (and it usually works in the FW world) with rearranging the rock work when the new addition arrives. This gives you a slim chance that the existing tang won't recognize its territory, and if that actually works, its the same as introducing them at the same time...that is if you can match size and maturity...
Even having said all that, please examine the cause/reason you think your yellow died, because it will give you a lot of answers as to what to do next...