I have not seen the insides of the 4329, but have on other models.
These hidden fastener lenses are typically mounted from the inside of the cabinet, access is with the woofer removed. If experience with JBL's larger speakers holds, the clearance is tight.
I have some pictures of the M2 lens.
I recently measured a JBL D2430K compression driver and M2 lens. My goal is to build an M2 clone. The speakers are going to go into individual boxes allowing me to stack the woofer and D2 into an M2, or even include a midrange. I got a pair of B&C 5NDL38 for cheap, and if they don't work I...
www.audiosciencereview.com
I would carefully remove the woofer, confirm that the bolts are accessible. If so, should be straightforward.
Take photos as you go. Polarity, connectivity, etc.