Credits to Atherion.
1. Freecam about 9 blocks away from a wall.
2. Break 1x4 hole up the wall.
3. Go out of freecam and walk up to the wall where you broke it and walk inside it kinda.
4. Turn on Sprint/Sneak/Flight and reconnect.
5. Hold whatever you use to move forward while reconnecting.
6 Magic! Your on top!