I was wondering, where exactly do you find the blueprint?

I'm completely new to modding so I have no idea what anything is.

Hey guys I need help with something: I'm playing with the Tengu ships and in the download thread it says that I can change which vanilla ship it replaces by going into blueprints. I've been looking through everything and I have no idea where this blueprint is. Can anyone tell me where it is located ...

Some person earlier also asked this but was ignored.

How exactly do I access blueprints?

Additionally, when I try and choose the ship, the game crashes.