I cant remember where I got the bmw h7 adapters, They were just the generic £3 ones of ebay if i remember. Why BMW couldnt of just used a normal fixing I dont know as they are a pain.
something like this:
https://www.ebay.co.uk/itm/203716520706?fits=Car+Make%3ABMW&_trkparms=ispr%3D1&hash=item2f6e736b02:g:fucAAOSwaXlhn1EW&amdata=enc%3AAQAGAAACoPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSjVt3vLKCbov98Z19qhuwY87apFqC%252B4FPGda5r%252B%252Fxlf8IR6wFmc7LRY%252BTgCAiJILqPIdUtsAMo6rE3RzRhNlVLc%252F%252Bpe%252B7m54jGOcQiFGUuUamfv0FJo85lBMiaAuHfQdEJkSRST8T3WIoIy4G8LZmHw5lkC37AdPEoGYWrZkbJy2g%252FYgIA9d75xtfZQg19i553ogu3dfhVEmw3J1UnVTYbhfBx3Hiy%252F3q8wXNoYqJqWljha0a%252Fu9R4iEs4JYCKwnjbmF%252Fc8Znh14NJraodmGsrDk9JMXQQPawtKkgeFI7dmsYHPjxK0hPVyRiSygvdxbCm5TBD%252BmTOaAOtIwJGjGOmjZzNZeRTCz0NQ%252BWieAPpeUyO06U6MrcX4bHiffkRfwlRAryhuSzII5CwuOVU13E3L3wQ52mVHVFcEs8zfwoKR861SclSEaTY1AvlOQ1FM%252FlReleMeFiiJ%252Fx4w2tclQsy8Xi5kxX1lMOpaeIaizrzvulVWgLgNUNSSGUhFzIwLUmlI6%252B3sQB6sQfFkZoMmBDB1dq55UYbLXz4xbnlCYhYSf17ukr3QE7nfRCzRPTQkogQinMFX3vyGtCUiZ4KxrOnyqzCNH9UsgxHCKy4MG8PGXkWQ8QAcJjRiaskBKLDGDGFIRpSHNz6D0mOJJ4n3dJ2O8Hh%252BC5on8fhZoWgdNPEo%252Ft6%252F2rQjG9SDek1%252FXSXw5jz%252FHmTR4cJMbr7VHgWf6eXaZtz2OH97iEf2H7ZKkenlJhoSxZcYocf2OYyPA610cJrcCYecEV%252FT5IpIoMyclhJD5xqqB1mgR3L13A3j9fnjjAiKL7FiXS7uUS%252BCNDkoxjJe1tcAQ590Jkk3Zjrbg18A%253D%253D%7Cclp%3A2334524%7Ctkp%3ABFBMxIWo069f
They are flimsy bits of crap so the locking tongs can be bent into shape a bit easier.
The one part I struggled with is the little stick out tab lines up with the base of the led to stop it rotating but it would inevitable break free when turning the stupid adapter to lock into place meaning the bulb went in the housing and was locked in but could rotate freely in the adapter.
it makes clearer in this video:
https://www.youtube.com/watch?v=3OU7c8Vu6_s
I always make sure the housing is facing vertically (led's facing horizontally)