Absolutely, positively do NOT use a soldering "GUN" on ANY, ANY electronic repair. Firstly, they generally have a transformer built into the body, and leak AC current. Secondly, they are generally not grounded properly and this alone promotes static electricity which can destroy or (even worse) weaken semiconductor electronics. Thirdly, 100W is WAY too much.

You'd be better off getting a $6.00 pure resistance soldering iron from Radio Shack.