you need to go to Herbolegy go down the stirs that you will start on and walk straight
them you will reach a gate. cast carpay Retractum on it to open it. then you will be in a
cercle shaped room. in the middle of the room, you will find the spell book. just walk up
to it to claim it. i don't remember how to cast the spell.

Once you unlock the herboligy you must go down the stairs and turn left then open the gate
and then there will be the book in the middle of the room

grgfg