How do I clear the Unreal Engine 4 cache?

Hey guys,

Quick question:

How do I clear the Unreal Engine 4 cache?

Basically, I have imported a 3D model into UE4 as an .FBX.
After importing there were some bits of the model I decided I didnt want so I clicked on them in the editor and hit delete. I realised that the name of the objects I deleted were still in my assets lists so I removed them from there too.
(I also removed them from the library too)

Thinking they had gone, I rebuilt the lighting and some errors appeared! Object X,Y and Z (The objects I had deleted) had lightmapping errors. (Which meant it still had knowledge of them and spent ‘build time’ trying to calculate irrelevant information)

Where can I go to completely remove these objects from my system?

Any help greatly appreciated!

P.S. I also tried reimporting the model, but it still looks for the missing pieces. :frowning: