taking cuttings from umbrella plant

You may be a able to gentle remove the soil from around the main plant and see if the young shoots at the base have roots, If not then leave them longer,
Carefully remove from parent plant and pot up.
I think with Schefflera you can cut a leaf and its stem off and place upside down in a jar of water so the leaf if just above the waters surface. The leaf will put roots down into the water, the stem will die and tiny shoots will appear on the leaf (on what would of originally of been the underside) and then the whole thing can be carefully potted up.