I cut off the sleeves, leaving the seam allowance attached to the body of the shirt. I unpicked the shoulder and neck finishing seams. I removed the hem and cut up the sides. Most t-shirts are made without side seams, but I couldn't figure out how to make a better fit without adding them.
Once all the pieces were separate, I cut the body pieces and sewed them together. I didn't want to fuss with re-cutting the sleeve cap, so I gathered the extra. Even though I had re-cut the neck opening, I was still able to use the original finishing piece. I used part of the original hem to finish the lower edge.
Now that I know this works, I will take more care with getting the sleeve right or adjusting the neckline a little lower. These sorts of shirts aren't my cup of tea, but if I have to wear them, at least I can try to make them better suit my body.
Oh, and that blinding flash on my arm? It's a purple slap bracelet advertising the database we learned in the activity. I haven't had anyone question me about the shirt, but the slap bracelet has opened multiple conversations about services that the library offers.