Moderator's note:
Posts in the early hours of the morning (UK time) from new members of this site have a nasty habit of being followed by 'helpful' links from other new members. (i.e. they're poorly-disguised spam). If such a secondary post appears here, I'll simply ban both members, resulting in the removal of this thread and the link.
However, if it's a genuine post, the simple answer is 'not easily'. You could go to extremes and follow the sort of routines that boxers follow when they need to drop their weight down rapidly (e.g. to meet the qualifying weight for a big fight), such as going on very long runs while carrying heavy loads and trying to lose some fluid through sweating it out in saunas but otherwise all you can do is to follow sensible rules for dieting and hope that the effects start to be noticed quickly.
In that respect, this is a well-regarded website for advice:
https://www.healthline.com/nutrition/how-to-lose-20-pounds