If I was you, I will take plastic cup, drill a lot of hold for water can go thru then put the NEM in there, attach to the wall of the tank by magnet cleaner for treatment, I won't feed the NEM until it healthy, place the plastic can to the medium light with light current flow. For prepare his toxin release to the water, I will replace new carbon for every 2 weeks.
I have a lot of weak NEM as tear apart, no foot before but it is still alive. The main thing I need to do is keep the tank stabilize, the NEM will cover by himself.