And precisely what sort of diagrams are you after? Diagrams or photos? You'll need to be a bit more specific if you want some help. For example, if you wanteda photo of the instrument panel I would suggest here:
http://www.!!!!!!!!!!!!!!/
and search their database using the 'Lear 45' and 'cockpit' options.
Have you tried Bombardiers own site and downloaded the Lear 45 fact sheet (pdf) at:
http://www.bombardier.com/en/3_0/3_2..._factsheet.pdf