Hello All,
One day I noticed one of CCU button (Auto) popped of.

Now without that in place I can not select Low or High fan speeds.

It had 2 pieces that I retrieve. Spring and one white square pin which keeps spring compressed.
I tried opening ccu but don't see how to get to these button assembly.
Don't want to force and completely ruin the unit.

I show Kris(jamesdeen) pull apart this unit but don't see steps to do that.

Reason I want it fixed:
This is stock unit that came with car and is working perfectly.
I have replaced it with jy pick and that one is also working but I am feeling it results in less cooled air then my stock unit.
I replaced in winter and even at that time i felt it. So want to fix stock one and put it back and keep jy one for rainy day.

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1) '04 S500 Gold/Beige......120k Miles
2) '93 300E 2.8...Green/Tan MBTex..........202k Miles(and going)
3) '89 420SEL...Light Blue/gray Leather....155k Miles (Retired )