How much dismantling to replace battery?

Some people suggest that it is not necessary to remove the speakers, airport card, etc. to make a battery swap, suggesting that doing so is more likely to create a problem. Both iFixit and MacSales' tutorials have you disassemble several items, why? I would be interested to hear suggestions as to why one way or the other is better.

Replacement battery was installed this past weekend, absolutely no issues. I went into it with Dan's advice in mind, but once I opened the case and saw exactly what was there I proceeded without removing the multitude of parts as per the instructions. Taking precautions to keep the glue remover away from all but the battery, I was surprised how easy it was to get the battery out. I used dental floss to gently saw back and forth, the first cell came out in less than ten seconds, I then loosened the other three small cells. When it came to the two large cells in the middle, I tried removing them with only the floss and no liquid remover, it seemed to work just as well without the liquid remover. I think the floss cut so well that the remover really wasn't necessary. Overall a very easy job and I felt much better not having removed the other stuff.