Ahh just found this question, minhaj.
You can kill the fungus if it is new / alive with a 50/50 ( by volume ) mixture of cloudy ammonia ( household ) this ammonium hydroxide at 18gm/Litre and hydrogen peroxide 6% w/v ( hair bleach ).
Mix and use. It does not store well. As all ways Do Not let this mixture get into the lens cement.
If the fungus is old it is probably dead and will have etched the glass.
Best Regards
Rob.