Can the president of the united states remove his signature from a law after he signed it?

no they can not "unsign" it but they can The President may sign the bill at any time after its deliverance. If it sits unsigned for more than the 10-day period, it becomes law regardless of his signature or not. Normally, it is known if enough members will vote to override the bill two-thirds is needed

answer; in stage 6; morality of individual principles and conscience;