For get a inert spawner you will need make a like in the ritual of corruption with the spawner in the center (draw with chalk and put the candles) and put an ender essence and a monster focus. For take you will need cast the spell rift in the spawner holding shift.
I got this information at: https://github.com/Mithion/ArsMagica2/issues/532
-(S) Mob Spawner (Found in the wild) -(C) Wizard's Chalk -(W) Warding Candle x4 -Ender Essence -Monster Focus -Spell: Touch, Rift Storage
-With the Spawner at the center, and using a Wizards Chalk, draw the same pattern as the Ritual of Corruption.
Drop down the Ender Essence and Monster Focus next to the Mob Spawner, and then cast your Touch(Rift Storage) spell on the Mob Spawner.
If done correctly it will drop an Inert Spawner.