Do you still have the part that broke off? If so super glue it back on. Best to do this with the cluster out. More room to work.
With the broken piece glued back on you can then reattach the big round plug correctly. After hocked up used a marker of some sort to draw across the plug onto the cluster, so if the part breaks off again, you can at least line up the marks.
If you have lost the part that broke off go to a junkyard and practice with their clusters. You should get the right idea of lining up the correct pins this way. Look for a car that has the dash removed. More clearance to see. Always a cluster laying around somewhere. I go to Pic N Pull around here. Two bucks to get in is cheap insurance.
