Need help printing on nylon or polyester shorts

I need some advice on how to screen print on nylon or polyester shorts. I need to print some life guard shorts. They are navy with yellow ink. Small logo on front and back of legs. Will I need an underlay? What kind of ink do I use. I have heard about adding nylobond? What is that exactly? Should I purchase this to add to plastisol ink or is there another special ink to buy specifically for nylon or polyester?

Thanks for the help.