Never had one out so can't help there. Must be some screws or snap tabs.

 

it is not wiring! and dont spray anything inside the cluster! it is solder joints and bad resistors. i sent mine to www.gmgaugerepair.com They take care of all the known issues with your cluster including the gauges,gear indicator,bulbs and the power loss problem. And you get YOUR original cluster back not a remanufactured one.

 

Try this website for some possible help for a do-it-yourself solution.
mrfixit.webnode.com/step-by-step-instruction/ This describes how a guy fixed his on a GMC truck. I'll try this when I have the time to do so on my 2004 Suburban Z71.