Just watch the video, links to the parts are below. :rtfm:
[video]https://www.youtube.com/watch?v=naOk1-738Vg[/video]
Here is a link to the part you will need
https://www.digikey.com/product-search/en?x=21&y=11&lang=en&site=us&KeyWords=BA17807T-ND
Looking at the CMOS LDO Regulator from the front (legs facing down, numbers facing you), the left leg is input (12v), middle leg is ground, and right leg is output (7v)
[video]https://www.youtube.com/watch?v=naOk1-738Vg[/video]
Here is a link to the part you will need
https://www.digikey.com/product-search/en?x=21&y=11&lang=en&site=us&KeyWords=BA17807T-ND
Looking at the CMOS LDO Regulator from the front (legs facing down, numbers facing you), the left leg is input (12v), middle leg is ground, and right leg is output (7v)