The question looks to be funny but yet it’s a serious question when one see it with deep meaning.
For layman and a budding astrologer or someone just have interest in astrology will give a simple answer that one can not get rid of rahu mahadasha.
It is true in one sense, but here the question is been asked because of it negative impact which is causing troubles and problems in a native’s life and so he wants to get rid of it ( rahu mahadasha ). As I always tell in many of my articles that astrology is purely understanding. The more you understand, the more you can get help from it ( astrology ).
Let me try to explain the concept with an example.
Suppose there is a bad man ( goons ) who has intension to harm a native who is very weak and can not fight with that bad man.
The native has two options with him :
Either to fight with the bad man and control him OR to make relation with him so that he will not harm the native. The relation is not a friendship kind that he will accept all his bad habits being a friend. NO NO only relationship to keep him off from his cruel intension on him.
In astrology also one can implement the same idea by aligning himself with the significances of rahu as per the horoscope, so that it do not give trouble or create problems for you again.
This is a golden Idea which every person after understanding can implement in their life. Of course one need to learn astrology as well.
Here a pure understanding of astrology does / can many a times makes life more simpler and easy.