Question about Soldering Irons

At 7 minutes in on the video below I'm playing a Electrician simulator and you use a soldering iron to take off a integrated circuit on a sound card and use the same soldering iron to put it back on. My question is do you really use the soldering iron to take it off AND put it back on? It seems to me that there should be a method to take it off and another method to put it back on.