HINT; under hood see where speedometer cable goes; if it has a "cable tie" attaching it to back of engine in oil housing area; remove cable tie(you can put another one on after the job); this will allow the cluster to come out further to get to items that need to be unplugged or unscrewed, such as oil line, & speedometer(makes it much easier & more room to get your hand behind it) as Jim states, the non insulated spade lug going to clock; seems to be only thing that can blow a fuse if touched to back of metal on inst. cluster; after getting tired of changing fuses every time i pull cluster ; i change mine to insulated one so doesn't blow fuses anymore when cluster removed you can take inside on table & work on it where it is warm or cool inside; you can also remove & check all light bulbs & clean then; even install brighter ones in the 2 dash illuminating sockets;if your dash light dimmer is not working properly, now is time to change it or you can solder a jumper across it to stay on bright all the time, believe me in my opinion it will not be Too bright ; I leave mine on full brightness all the time; (did this once to save money) i also repainted all the instrument hands, couldn't find florescent yellow, so used flour.red paint
Steve