1- Fisrt, I cut the neck about 3cm away from the original neckline, as you can see in the picture:
2- I cut two strips at the bottom of the t-shirt. This way, I made the t-shirt shorter (it was very long) and I got two strips that I’d use later on:
3- I cute the sleeves along the length, without detach them from the t-shirt, as you can see in the picture:
4- I made two small cuts at both sides of the t-shirt, at waist level. Then, I put one of the strips through both holes.
6- Finally, I cut the other strip in half and with the two resulting strips I tied the shoulders of the t-shirt.
7- To wear it, you only have to tight the t-shirt to the waist with the strip, and made a bow behind. This is the result: