Here's one way to do it, found on web search:
How To Tailor A Uniform
" Well I couldn't take it anymore. I go to class, I love working out, I love sparring, I love feeling empowered but I hate my uniform. It is so big on me and makes my 105 pound body look, well, like a 300 pound body so this week I cut up my whole uniform, added darts and let me tell you, I love it. It feels good. I am confident, I can move more freely and I look like myself. Not like a woman hiding in a mans uniform. For anyone who is interested. I am not a seamstress. Actually, I am horrible at sewing, so what I did can work for anyone.
I just took a suit I had, and traced the darts on a piece of paper. Making up the three pieces - like pattern pieces, of the suit front and the same with the back. Then I just traced them right on to the front and back of my uniform shirt. I cut down the division line of the three pieces! and then just resewed them back together, using a half inch seam. Then I just had to rehem the bottom - since it ended up shifting a bit. I just love it. My uniform fits me perfectly now. Just enough room for my chest. The back does not bulge up and you can't see my stomach out the sides any longer. And since I did not adjust the arms at all, it does not inhibit my punching, blocking or striking in the least.
The pants I had to make different adjustments to. I added darts, front and back but needed to keep the waist big, to fit over my hips, to put them on. Also, I wear hip pads when I spar - they are the best, no more bruised hips - so I needed to maintain room for those, however, the biggest adjustment was simply raising the crotch area. To do that, I just turned the waist down one and resewed it in place, rising the crotch area. I can kick much more easily now, and don't spend half my time, hiking up my pants like I did before.
Anyway, I just wanted to share my new found comfort. You can't imagine what a difference feeling good in your uniform can make. It sure has made a difference for me!!! Thanks for letting me share!"