If similar to 35i, just need some luck on your side. I didn't get mine all the way on and boost popped it off right into a serpentine belt pulley and it cut a hole so JB weld to the rescue !

Open the coolant reservoir so no pressure or vaccum so the hoses can compress and search YouTube for a video showing the process.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)