Harman-Kardon sub woofer question
 

I'm trying to fix a woofer that is having a problem in its amplifier
section. It is designed to work with Harman-Kardon system HKTS5.
However, for some strange reason I am unable to remove the amplifier
section from the enclosure (this is a 120v/ 100w woofer). I took out
all the screws on the back side and accessed the amplifier from the
big opening reserved for the speaker. I don't even know if the
amplifier unit comes off by pushing it out from the inside, or whether
I have to pull it out from the inside and out the speaker opening. If
anyone has had any experience with these, please give me some tips.
Thanks a lot !