That's the good thing about the 760/7600s is that they are so easy to take apart, including bbl removal.
Remove front and rear stocks.
That tube under the bbl is actually a long bolt that tighens up on the lug on the back of the bbl. It should have four holes on it near the receiver. Just take a Robertson or Philips screwdriver that will fit closely into those holes and loosen it. I put the screwdriver across so it engages two opposing holes. Screw that off and off pops the bbl. Pull out the bolt carrier/slide rails, remove the long bolt from the slide tube, pop out the drift pins from the trigger.
I clean all my parts under very hot running water in the sink. A toothbrush helps here. Make sure all is dry and lightly lube with a spray oil.