Start where he is and move out

"It would have been pointless to simply undo the errors in Jose's view of the world and supply him with information. It was essential to stand beside him on whatever solid ground he might possess. The learner, child or adult, his experience, his interests, his concerns, his wonders, his hopes, and fears, his likes and dislikes, the things he is good at, must always be at the center of his learning. He can move out into the world only from where he already is in it."

John Holt, What Do I Do Monday pg 37

When an older child struggles with reading, it is because he missed something along the way. You must go back to the beginning and start anew. When he finds the piece he was missing, he will quickly catch up to where he should be. All learning is like this. Just as when I learned how to do story problems in 7th grade. The teacher had to start with where I was. Find a connection to the child, make sure it applies to them. Then and only then can you move forward.