Need a bit of advice

[XCypher]

So I have a killer 705 clone that I can't setup due to the ceramic cup being too snug to the centre post. 1st attempt of just using a file wasn't so successful, so before I go and see what else I can do to widen it out by just a mm or so. Any advice on what you guys or gals have done with said issue would be awesome. Thanks

 

[Projectguy]

Do you have pictures?

 

[XCypher]

I didn't take any pics as it's just a ce2 ceramic cup but sure I pulled this off google
Google Image Result for http://www.imgur.com/RO02j.jpeg