Simba: go left at spawn, go outside, wait for outer gate and hit the switch (don’t go to elevator) and then go back and the gate that leads to a cliff edge will open, go over to the edge and you will get simba.
Zazu: go right at spawn, progress the map until lower gate, wait for lower gate to open and the jump pad next to the large pillar will open, use it to jump up to the pillar for zazu.
Mufasa: go in the upper tower door before the final elevator.