86 gl markland top box light rail install and also trailer hitch with markland bottom light bar

[86 goldwing]

hi all first time posting here so bear with me if i ramble on long
just picked up the upper light bar and trailer hitch of of kijji
ive been looking on line for info on how to install these with no luck
hoping someone on here might know how to do this
and while we are at it need help with new dash lights not real sure about the right bulbs to use
looks like wedge 194 but they look to big in the pics ive seen on amazon
any help here would bet great thanks mike c