hello everyone ,anyone konws how to disassemble 1990? I have remove the plastic rings outside the cans. but i can't take out drivers.

Hi everybody，i'm new. Visited headfi for almost 6 to 7 months now and wanted to be part of them. currently i own mojo, dt990 32ohm,dx90,ex1000,and amps. and i love to listen to metal sorry for my english since it's not my native language