I think jawquin answered your question, but I don't think you asked it correctly.
Jawquin posted a process of butterflying a pork loin, which I think you wanted.
You asked for a video of butterflying pork "tender"loin, which is a different cut. It is much smaller in circumference and to butterfly it and stuff it would be extremely time consuming, and would probably dry out a tenderloin.
Just making the clarification, more for future search references on butterflying these two different loin cuts.
(I keep part of a freezer shelf loaded with pork loins all the time. I have never butterflied though. I prefer to just stuff them from the ends. Heres a great Roadmap thread for stuffing ideas, regardless of method:
http://www.bbq-brethren.com/forum/showpost.php?p=118280&postcount=4
Good luck!!)