Editing collisions on a blender model

[Cag93]

I've come to the conclusion that blender absolutely despises me, so I need help with a mesh that I've changed the collisions on. If someone could export the mesh properly for me (Or edit it themselves, in case I imported the mesh incorrectly too. I only deleted a few vertices, it's not too much editing), that'd be great. If anyone wants to help, I'll put the file on megaupload or something. It's the one room mesh from mothership zeta where the death ray is. There's a giant pillar of collision in the very center, where the core is supposed to be, but I'm trying to make a room with that mesh, so the collision prevents me from walking through the middle of the room. I went into blender and deleted the pillar, but now it won't export :/