Large STEP file from a supplier

Hi,

It's my first post here and english is not my mother tongue so be understanding.

I have a complete motor from a supplier in a heavy STEP file (171 Mo)

I'm able to open it (takes about 3-4min) and it's composed of 7159 surfaces and 4 imported bodies. I can't even make a repair/diagnostic on it... it crahes everytime.

I've tried to export to STL and reduce faces with MeshLAB but I lose to much details and lose originals plans. I've tried to "defeature" overnight but it still crash.

I'm looking in a way to keep the exteriour "shell" but suppress the internals part/surfaces...

Anyone?

Thanks in advance

Phil

SolidworksImport export