On the 850s there are screws behind the heater control knobs (at least on manual climate control model). You can gently pull off the knobs. The center console needs to come out for the gear indicator and is held by if I remember 4 screws.

I think there are posts with details on these.

My purpose in replying though was to say I've had these lights work intermittently. This to me points out a bad connection or bad ground - it doesn't prove your bulbs aren't burned out - just may be worth looking around at the wiring when you open things up to ensure your new bulbs will continue to shine.