I am very heavy handed with planting and need tools for planting most anything. Use tweezers or forceps with the point at the bottom of the stem and the forceps arms surrounding the fragile stem and plant with a little bit of a scoop to get the substrate to hold the stem down as you remove the forceps. I leave leaves on the stem to help anchor it.
Hope it is a weed for you like Najas. Sure a pretty plant.