I think either out.BV or rst2 works, they should have exactly the same content. Then follow the tutorial, rename out.BV to in.BV, and set usedata=2 in.BV 1, the last number representing the way of branch length value transform (see
dos reis & yang 2011) [but this may not be very important]. Should further Qs, pls don't hesitate to post your Qs here. thanks!