And a Transparency Map is just another texture. Except, instead of picking a colour, you have a numeric setting. Set the value to 1. Connect the transmap texture. And there you are.

See how the black areas have vanished.

It's often a good idea to connect the transparency map to the Specular Color, which stops any reflections. Have a go with the Transparency Edge and Transparency Falloff dials to see what they do.

And the way the shoulder-strap vanishes? That's down to the limits of Posette.