making a t-shirt larger

[erika]

So I got this awesome shirt from the ACLU and, sadness, it doesn't fit. (It's about 5'' too small at the sides.)

I found How to make a T-shirt Larger or Smaller, but the instructions are kind of sparse. Does anyone have any other ideas?

I'd love to do something with corsetry type lacing, but wouldn't that work better if the shirt was too big?