I can help you.
[video=youtube;L531i3OnCUM]https://www.youtube.com/watch?v=L531i3OnCUM[/video]
But seriously, I can. I swapped my downpipe a few months ago. My bud Daniel helped me, and we both have a black 2015 Fiesta ST. Now the odd thing is that while his car had downpipe bolts, mine had the studs. They were built a few months apart. So lucky for me I'd obtained both parts in advance just to be safe since I'd read here and there that some cars had studs and some had bolts. I advise getting both, then return what you need later. That way you don't have to have your car apart and be waiting on parts. Here are the part numbers:
*W711242-S300, Turbocharger to Downpipe Stud, qty. 3
*W715974-S300, Turbocharger to Downpipe Nut, qty. 3
*W715681-S900, Turbo to Downpipe bolt, qty. 3