AutoCAD Inventor :: Export Large Assembly To Step File?

In my company we work with quite large assemblies, a small project im working on now, contains 527 documents with a total of 3088 occurrenses. Our customers often request STEP files which is a real pain for us to create.

Usually we have to start exporting the assembly at closing time and let the computer work over night, and the product is often a file in the 200mb range, which is too heavy to handle via e-mail, and also takes a lot of time to import to other CAD software.

Using the Task Scheduler is not an option since our file server isnt compatible and refuses to let go of files unless they are checked out manually.