I'm in a similar situation only I'm the son. My dad has a old 91 4runner that he started work on because the heater control broke. He had to take the whole dashboard off to work on it and never got around to putting it back together and he has since told me that if I can get it out of his garage it's mine.
Time wise I'd say your looking at about an hour to take it apart and can't say about putting it back together. I'm starting the process of putting it back together without having been the one to take it apart. I did find this video that can get you started it's about swapping out the dashboard gauges but it looks like it's almost the same work to get to the dashboard dismantled.
91 4runner gauge removal - Bing video