The tuning is good old standard CEGACE. Low to high.
I love that it’s a Bb tune but we’re playing down around the 5th fret. (Typically my head tends to put me up at the 10th fret for Bb.)
(Click on the Flat logo to see/hear the whole piece.)
Here’s me (and my hairy legs) and my RAM Speak Easy 8-string (I only use the top 6 strings for this.)