Radhey Radhey,
I can assume that Maharaj ji is referring to the conditions of the path of bhakti that have to be understood and adopted before one can successfully attach their mind to God. In brief, they are:

1) You should never ask God for any material thing. If you are asking God for material things during your devotion, it means that you are desiring the world, not desiring God. Then it means your mind is in the world, not God. You should not even ask for liberation, because that also means you are not attaching your mind to God, you are just asking for something from Him. You should only desire for His darshan and His prem, then your mind will get attached to Him.
2) Instead of worshiping God as “God”, adopt one of the four ways of feeling related to Him: dasya bhav (loving Him as a kind master, and you are His servant); sakhya bhav (loving Him as your friend); vatsalya bhav (loving Him as your child, and you are His mother or father); or madhurya bhav (loving Him as your beloved).
3) You should be ananya to Him. This means in your heart you feel related only to Shree Krishna, you depend only on Him, and you desire only Him, not anyone under maya, including the devtas in swarg (Indra, etc.). This is exclusiveness in devotion.
4) Once you have understood and adopted these points, you have to attach your mind to Shree Krishna by doing ‘roop dhyan’. Roop dhyan is a style of meditation where you form an image of Shree Krishna in your mind. In other words, you meditate on His form. You can also think of His leelas. The reason roop dhyan is important is that if you are not thinking of Shree Krishna’s form, it means your mind is somewhere in the world – then it is increasing its attachment to the world instead of Shree Krishna.
 
I have only described these points very briefly. For a full description, please read “Prem Ras Siddhant” by Jagadguru Shree Kripali Ji Maharaj.