Remove dusty fragment inside the back lens In Fujinon Super EBC XF 16-80mm 1:4 R OIS WR

Remove dusty fragment inside the back lens In Fujinon Super EBC XF 16-80mm 1:4 R OIS WR

[@justafuji]

I just cleaned my copy of the 16-80 that had a dust speck behind the rear lens group.
Though my copy also has some fungus behind the front element. Do you have any idea on how to remove the makeup ring on the front of the lens? I cant find any video/info regarding this. BR