yup -thats right - don't have to take anything apart - just get a spanner on the tensioner and take that bolt out (back of the pivot is threaded, so no nut to loose).
then get that hex key on the centre of the pivot.
the bit with the hex hole is effectively a cap that threads onto a tube , retaining the pivot on the tube.
the other end of the tube is threaded (with an oil seal) and threads into the head.
when you undo the hex nut there, either the cap could come off and allow you to slide the broken pivot off, OR the tube could come out of the head with broken pivot attached (which happened on mine)
I think either is fine, as long as you have clearance.