If they are already 2 months old, they must have thick stems so LST will be tough but not impossible. I would recommend you do as the last poster mentioned and slowly and gently tie down branches as much as they will go without snapping and after a couple days while the plants get used to the low stress and their stems become more malleable so you can tie them down further. You should listen to your plant though, as you are doing it to make sure you're not causing too much stress/strain