Stainless steel countertop a bit too small, tips?

[JMVN]

I have ordered a bent sheet of stainless steel to place over a metal frame (so that it covers the entire frame, like the lid of a shoebox). It's supposed to be a kitchen table with some storage. Now it seems that the measurements of the sheet are not quite right; it's a bit too small to fit over the frame. I've gotten three out of four corners in place, but then it stops. It can't be more than a few millimeters off.

Is there something simple I can try to get the sheet in place? Or will I have to try to reshape the frame to make it smaller? It would be disappointing to have to arrange for a completely new sheet when it's so close to working. If I had a very large oven, maybe I could expand the metal in the heat, but in the absence of that, I'd gladly accept other tips.

 

[pelpet]

File the chassis on all sides followed by some old classic violence?

 

[tommib]

Make sure to have at least two people (depends on the size of the disk) so that it goes straight onto the base.

Then Vilja,Våld,Vaselin

 

[JKrister]

A picture says more than a thousand words.
File down burrs on all corners of the base and try to get it on straight, across all corners simultaneously.

 

[JMVN]

Thanks for the tips everyone! I'll try filing and calling in some reinforcements.

 

[JMVN]

Thanks again, worked with a little assistance and a hammer. Now it should be in place.