How does one get rid of jealously and envy from the heart?

The following is an extract from Bahisti Zewar, which answers your question.

The harms of jealousy and its cure
When you see a person living comfortably, eating and drinking well, living with honour and respect, and upon seeing all this you begin to "burn" within you, begin to have hatred for him or become happy when he experiences any lapse - then this is known as hasad (jealousy or envy). This is a very evil characteristic and is also sinful. Such a person passes his entire life in bitterness. In other words, his worldly life and his Dînî life are both abhorrent and unpleasant. Great efforts therefore have to be made in order to come out from this great calamity.
The first cure for this is that the person should think to himself that "by my envying him, I am causing harm to myself and no harm whatsoever is befalling him. The harm that it is causing me and my loss is that all my good deeds are being wiped out." This has been deduced from a Hadith in which it is mentioned that hasad devours good deeds just as fire devours dry wood. The reason for this is that this person is indirectly forwarding an objection to Allah by saying (indirectly): "so-and-so person does not deserve those bounties. Why did You give him these bounties?" If someone raises an objection to Allah in such a manner, how serious a sin it will be? It is obvious that such a person will always live with malice and sorrow in his heart. As for the person who has been envied, he has suffered no loss whatsoever. By your envying him, the bounty which he possesses will not disappear. Instead, the person whom you have envied will benefit in the sense that all your good deeds will go to him.

Once you have thought over all these factors in your mind, praise this person (whom you are jealous of) and say good things about him to others. You should also add by saying: "All thanks are due to Allah in that he has all these bounties. May Allah give him all these bounties two-fold." If you happen to meet this person, meet him with respect and humble yourself. In the beginning, your soul will be greatly burdened in doing this. However, hasad will gradually disappear from your heart.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai
FATWA DEPT.