HI, I am hoping someone can guide me to a service manual or just how to get inside this speaker cabinet to find the fault with one of my speakers.

I have removed the grills, taken the speakers out, removed all the long screws (x6) but am worried I might damage the plastic case as it appears otbe glues tight!

Only the tweeter is working but is quite indistinct,  the other speaker cabinet is operating as normal.

Apologies if I am in the wrong forum

regards

Ewen