After I did it I thought of a better way. A quick run down
-I cut the grey one piece suit from the high waist, you want enough fabric for the armpits so I made sure not to cut too high
-Took thick black nylon tights and used it to made a shirt and sew the cut off pants on to it so it stays up (the reason he can’t raise his legs up is because the one piece suit borrows fabric for both arm raising motion and leg motion that’s why you need to separate them)
-Next is the shirt that was cut off, used a thread ripper and opened up the back seam to about 1cm below the neck collar. This allows the arms to rotate forward 90 degrees
-I used a clothing iron and folded all the seams and sew up hems from all the cutting so the fibers won’t run off
-This is where I noticed if I make him do a sitting pose the pants will drop too low and you can see the black nylon shirt that I sewed on to it
-If I kept some of the fabric attached to the back of the pants this would not have happened
-To fix it I made a nylon belt that you see in the second picture to cover that up, the belt is very tall, it extends up to the chest and won’t ride up or fall off from continuous handling