[The Glademister]

I'm pretty sure what you're referring to is part number 477 511 515, camber eccentric. A pretty nifty piece of hardware that not only secures the end of the rear sway bar but also serves as a rear camber adjustment. There is no need to loosen the bolt on the inside of the trailing arm but you will have to take off the nut on that bolt to get your sway bar on. There's a large bolt head (19 mm?) on the outside of the trailing arm that you can put your wrench on to keep the camber adjustment while you loosen the nut. As far as rear sway bar adjustment - that would be multiple bolt holes in the ends of sway bar. The 968 M030 rear sway bar has three adjustment and there's one available from Lindsey racing that has five. I think your OEM 19 mm sway bar probably has only one attachment option.