I don't know how applicable this is, but I have replaced a tweeter on one of my N801s which have a similar looking mounting on the top of the enclosure.
The replacement was pretty easy. The rim around the front of the tweeter housing is a twist-lock and once it is removed the tweeter will slide out with a forward pull, enough to disconnect the spade lug wire connections. Once this is done the tweeter itself will simply pull off of the "tail" to which it is attached. Installing the replacement is a simple reversal.
Bill