How to Get to Rennala, Demigod in Academy - Elden Ring

You will need to go to the main academy gate.

And go up the elevator.

After that, move inside the church of the cuckoo.

Activate church of the cuckoo grace.

Then activate schoolhouse classroom grace.

And go upstairs twice.

You have to summon the players to help you.

After that, you have to defeat the red wolf of Radagon.

And activate the debate parlor grace.

Go meet moongrum, Carian knight.

Attack moongrum with scarlet rot.

After that, wait for Scarlet rot to kill him.

Finish him and get the Carian knight's shield.

Wield Carian Knight's shield.

You can use the lift to go up.

Open door for Rennala demigod fight.