How do I get this to fit?

This is a pic of the rear sway bar on a Mk 2 RS2000 (mounts to chassis). As you can see the urethane is narrower then the hole.
How do I get it ito fit?
I've gone back to the Suspension shop to check the right part was ordered. I've checked this against another sway bar and they are both the same width.
Do I grind the metal hole to match or does the urethane compress to slide through, then expands when it comes out the other side?
Help.
How do I get it ito fit?
I've gone back to the Suspension shop to check the right part was ordered. I've checked this against another sway bar and they are both the same width.
Do I grind the metal hole to match or does the urethane compress to slide through, then expands when it comes out the other side?
Help.