I boiled water and did it with mine and disassembled everything. There's 4 parts. The "trunks" pelvic rubber overlay, the inside torso ball joint (hard plastic container within the rubber diapers that slides out once the rubber gets hot enough), right leg (male peg hip joint), left leg (female hole hop joint). I disassembled them and the problem was the pelvis was slightly bent inside the overlay, causing one of the legs to hang lower than the other. The hip joint (right, female side) also wasn't snapped in all the way from excess plastic inside the ball joint which caused gappage. Once you mess around with it, you can get them even.
I'll look into this then, thanks. Bugs me that I'm forced to do some sort of walking pose with Sarah because of it.