Need Tutorials and Advices on Project

Hi Everyone!
So I have a max file which is created by an architect. Everythings so messed up, all the windows are seperate objects and things like that. How do you guys normally work on this kind of projects? Project file is big and it is hard to navigate, too. Thanks for any tips or helps. Also tutorial links are very helpful if you know any.

Up up :frowning: Also sorry for posting to wrong forum, ( if it was wrong… )