All that must be done to return to Heaven is to reverse the original error when Love was replaced by fear, Oneness by separation, and Eternity eclipsed by time.
The reversal begins with the recognition of the original error and the desire to let it be corrected.
Struggle and effort are not needed.
It is not necessary for you to correct the original error, indeed you cannot.
The Holy Spirit has the function of undoing the falsity in your mind, with your willingness and cooperation.