The support bearing flange (BMW's words, not mine) in my opinion is an over priced part. It consists of an aluminum "cup" with three studs sticking out of the top and a small rubber, metal sleeved, bushing in the center. I could not find just the rubber bushing as a separate part. This bushing centers the piston rod like any other suspension bushing works.

Mine was cracked along with the bearing guides being totally destroyed/flattened.
So, I went ahead and replaced it. BAVAUTO offers a "Rhine" brand for $70. I went with the BMW OEM flange because I could not find any information on the Rhine brand longevity. I may change the other side with the Rhine part for comparison. Its all in how long that rubber piece holds together. I don't think the clunk was because of the bushing being torn so much as the guide supports (the foam pieces) being totally gone that allowed the shock to "bounce" against the top of the shock tower. The torn bushing would probably allow the strut to move off center which could shorten the life over time.

When I do the other side I will not order the dust boot as the original was dirty but appeared no worse than the new one. If you have to order parts before you take it apart you may want to get it in case its in bad shape. About $22 if I recall so really not worth not replacing it.

Do plan on replacing the rear control arm nut, the shock nut (large single one), the bearing flange nuts, the shock mount "pinch" bolt, the upper "wishbone" pinch bolt and nut (mine totally flattened the threads apron removal) and possibly replacing the sway links since you're "already there" and have to reeve one side anyway. You don't need to drop the sway link, just the upper side and swing it out the way. No need to drop the splash panel under the engine.

You will have to remove the plastic (probably broken and cracked) pieces on the cowl below the wipers. This is very easy and not worth explaining here other than you need a 13mm wrench to turn the plastic nuts holding them in place. 10mm to remove the lower pieces after that then your done in the engine bay for now.

Also pay attention to the orientation of the prop shaft as it has to in a certain position in order to pull the entire spindle down to get the strut out from under the wheel well. You can do it by feel but it helps if you look at the diagram ahead of time. Also loosen the hex screws holding the sensor wires and brake line so you don't put too much stress on wither as you pull down on the spindle.

This is 4-5 out of ten in ease if you're used to DIY. The sway link would be a 1 for whatever thats worth. From the time the strut is in your hand to putting it back on the car should take no more than 30 mins. The rest of the time is getting to it and buttoning it all back up. The second one will take half the time.

And FYI, I used my Makita 18V impact to compress the spring and it worked perfectly. Much faster than by hand with a ratchet. The detailed instructions for all this are available on this site. Just do a search. I never could get the exact torque values. So far now I used 20 years of wrenching experience to determine how tight. I erred on the low side and when I get the actual numbers this week I'll check all the fasteners again. I am not driving the car daily in the meantime for no other reason than I don't have to.

Good Luck! I am half asleep so forgive the rambling sentence structure...

If someone reading this can provide the torque values it would be much appreciated:

31 12 2AZ (I get the 31 12 part...)
31 12 6AZ
31 12 7AZ
31 12 8AZ

I used 56N*m for the 6AZ (If I recall, I wrote it down somewhere) which should be about 40 Ft*lbs. and scaled from there. But, I may be thinking of some other bolt...Nevermind.