On my delta royale 1989, some of the lights are out. Part of the light for the following gauges are out or are partially out: Temp, fuel, voltmeter and oil pressure. Is there a way
that I could change these myself?

If you pull the dash cluster out, there will be a bunch of 194 lights on the back of the cluster, you can twist and pull the rubber housings and replace the lights. Granted the cluster is similar in nature to an 89 Bonneville.