If it's just superglued on, you can snap the SPS
off the plugs easily enough. If you think you're trying too hard, you can always use some dikes to cut at the base.
With softies, I just take a razor blade and slice off at and angle as close to the base as I can. Then I just rubber band it in place to a small rock and glue\epoxy the rock to the larger aquascape, or I just rubber band the softie to the larger aquascape itself. You can use a small dab of superglue if you'd like as well, but I don't bother. After a few days the softie has usually attached to the rock.