Ok got a dumb question.
I wanted to install led bulbs into the headlight and to remove this part in order to get bulb to fit. Then noticed the bulb clip uses it to hook onto. 1 what is this part? And can you buy a new one separately? Also is there a replacement for the clip so i donr have to put the whole part back in light? Thank you

 

Its part of the bulb holder as you discovered, it attaches to the boot. It cannot be purchased separately.

 

It is best IMHO if you want to go LED to change out the whole of the innards. Just putting in a bulb usually doesn't match the reflector. The light is not focused properly and dazzles on coming traffic.