You could camp on the ledge and force them to approach you. You can ledgehop super missiles to ledge regrab without a jump in between. If they're closer to you, ledge hop charge beam is faster and safer. Finally, ledge hop fair or zair when they're within range. Usually, spam like this will force your opponent to play aggressively so they don't have to deal with your spam. It should be easier to get them offstage this way. This is a rather cheap method, but easiest.
You can pressure your foe to retreat with repeated backwards SH zair. A forward SH zair gives Samus a larger frame, which makes your zair get less reach while closer to the ground. A backwards SH zair makes Samus do a backflip, significantly reducing her size. You can then use this to use a zair closer to the ground while still having maximum range. You don't have to even hit your opponent, just force them to retreat. Sooner or later, they'll get hit and you can land a hit to hopefully get them offstage. This is somewhat like a brick wall.