make sure the rockwool cubes are fully wet, place the seeds on their sides firmly so the seed surface makes good contact with the rockwool but not under the surface of the cube
put them in a air tight propagator or box with a little bit of water at the bottom in the dark, in a warm place, in 2-3 days they will crack and show the white tap root
when the tap root is .5 to 1cm long, place the seed tap root side down into the rockwool cube, so that only the shell of the seed is poking above the surface of the cube
then put them under the light, getting them under the light as soon as they germinate like this helps to stop them stretching
the taproot will grow out of the bottom of the cube, and the seed end will grow upwards and split open, and you will see the first 2 seed leaves
peace