You can follow this tutorial with any skintexmod you have, even if its already been made.
Making a skintexmod for dilldoe’s bodysuit is really easy. All you need to do is makesure you use overlay in config.ini. Open up your bodytex.png and stretch it to fit this red box.
I always just downsize my skintexmod and copy paste the arms to fit the bodysuit but you can draw on the red box instead of the bodytex.png if you want it to 100% match up.
Now save that, go into honeyselect, select the bodysuit(in tops) and use the skintexmod.
It should fit perfectly.