I poke my finger in the rockwool so a hole is created, this will be to suit the size of ur seedling.
I rip off some rock wool from the side of the cube.
Placing the rockwool cube on its side i insert the seedling.
I then use the rockwool i pulled off of the side to gently fill the hole. Place some inside alongaide the seedling being very careful and leaving cavities.
Then depending on the size either leave the head of the seedling outside of the cube or inside with a small bitnof moist rockwool down the side and just covering the hole.
Keep it all moist.