Thanks Very Much tri-comp for your post.
It was my bad luck because I had tried to open the the speaker from front and now the front side plastic is broken. but the speakers are in good condition, only the cable was damaged, so I have purchased a new pair of convationally available boxes from the market and have fitted the speakers in them.
Anyways, the info given by you can be of use for others so that they will not damage the box while opening.
Can you please send the complete service manual of FW-C39 so that I can use it in case if there is some problem in my system?
Thanks for your help.......