Others Diana Chaser Moderator question.

[gunhawk7]

I broke the moderator for my long barrel Diana Chaser, so I started to look for a replacement. There is an aftermarket moderator available for the pistol length barrel, but the male end of the long barrel front sight is much larger and I can't find a moderator to fit it. So, I was wondering if the long barrel end under the plastic sight is threaded, and able to take the short barrel moderator, and if it is, how do get the plasic front sight off?

Thanks for any help.