speaker repair

Need some help. I have dented the tweeter on my 685. The speaker operates fine since it is only 12mm diameter dent. But would like to replace the tweeter. Can someone guide me how to open the speaker and replace the tweeter. I am going to buy the tweeter from B&W. do i need special tools or any...

I have a pair of the original Ohm Walsh 4 speakers and last night I think a power transient damaged one of the woofers. The bass sound from that speaker is distorted. I am not sure how or if someone can fix this (likely a new voice coil ?) but I would like to know if there are recommended...