by carefully moving the fingers apart the bits usually pop out, if not it at least clears hair out of the area a bit so you can see!
female robo
male robo (though he was around 5 months when photo was taken, and so as older was a lot clearer)
shows the scent gland well that pic!
if you have another pair of hands maybe someone can take a photo when you have them in a position to see their bits