When I started working at my job we had temporary t-shirts before we got proper shirts, they were all XL and bright teal* and said ASK ME on the back in big letters. Now we have shirts the tees are unneeded but unwearable at present and needed significant adjustment.
I cut the section off the back which said ASK ME, and also the section on the front which said the name of my work, then sewed the top back on to the remaining body. I took in the side seams quite a lot because it was far too big.
Then I removed the sleeves and sewed them back on further up the arm (as the shoulder sat half way down my arm before). I basted the top of the sleeves and pulled it tight so it scrunched up, then I sewed over this scrunch with the sewing machine.
Then I cut a white square from the section from the back and a teal heart from some left over teal and sewed that to my sleeve.