While it may seem like it make sense to pray that Satan my change his ways, we know that is not possible. He was, is and will always be opposed to God. He is an evil, malevolent spiritual power whose single goal is to block God’s will. Satan’s ultimate destiny is a place Jesus talked about.

Then he will say to those on his left, ‘Away from me, you that are under God’s curse! Away to the eternal fire which has been prepared for the Devil and his angels!  – Matthew 25:41 GNT

It makes more sense today to be praying against him. We should pray that his plans will be blocked and those who follow him will not be able to carry out their evil schemes.

The Bible is all about God, and that is why the practice of prayer is so pervasive throughout its pages. The greatness of prayer is nothing but an extension of the greatness and glory of God in our lives. The Scripture is one long testimony to this truth. – Timothy Keller