For Morales to win he has to

fight with his head and not his heart
Make sure all the prep is done so he is 100% on the night
stay focused throughout and dont lose composure
Try to put Pac on the back foot
Hands should be high and adopt a stiff jab

For Pac to win he has to

Set the tempo and a pace Morales cant match
Make the Mexican use his ageing legs
Throw his punches in bunches
Be a more evasive target than he was against JMM
Employ a body punching strategy and stick with it

If both of them fight to the best of their ability its hard to seperate them . Erik is past it now but is still capable of skooling Pac even at 80%.It will be hard for Pac to reach the intensity of the 2nd fight so I expect Morales to be better and Pac not quite as good . I can even see a draw but if I had to go 1 way it would be the younger fresher Pac on points