Alright, I'll do my best....
For the Trip Computer all you gotta do is unscrew the cluster surround, unscrew the section of the dash where the trippie is.... Then take the trippie out, and remove the front cover of iot (its clipped on, be careful removing it... ) Now, once you have the front off it, there is the screen and a white rectangle piece of plastic (this is the filter that makes the light orange) remove this filter and replace with a same size piece of see through plastic (i got the blue from a document folder type thing from big W, many people have used colored post it notes but it didnt look too crash hot on mine) once your done, plug her in and presto!!! Same procedure for the climate control, however its got a bunch of little screws... piece of cake, i've only done it once and both the trippie and climate control took under an hour.
For the dash, same principle however there are heaps of screws... just remember where the long ones go etc etc and you will be fine....
1990 EA Fairmont Ghia