how to trim steel interior into the trunk

I have 2 inches of steel that i need to trim off the top of the opening from the interior into my trunk on my car so i can squeeze a pre-fab sub box in. Whats the best way to trim the steel so i have a clean smooth cut? Thanks!

Have you thought about getting an enclosure built?

got a good deal on the box a while back. I've already considered having another one build, but i think cutting is going to be a cheaper solution.

Where do you want to trim? Years back this was done on an early 90s Mercury Sable. (Cousin's Car) Couldn't "rock" the box in so he cut on each end of the back "rain gutter" and it allowed us to bend it up to gain enough clearance to get the box in. Bent it back down, silicone sealed the cuts and put the trunk seal back into place. Never leaked. A reciprocating saw with a metal blade was used to make the two cuts. Maybe think about cutting/bending instead of removing all together? Otherwise if you must remove the material, a jig-saw or saw-zall with a GOOD QUALITY blade should do the trick for you. Be patient and cut slow otherwise you will just eat up blades and make a bunch of extra heat. If you have to cut, I would get some door edge molding to cover up the exposed metal to save your fingers at a later time. Or even split wire loom at the least...

When i pull the seats back to expose the trunk, i am cutting 1-2 inches off the top of that hole. So the processional recommendation is a reciprocating saw, than? I want it to be a clean cut, so i think im going to sand it when im done, and cover it with a weather strip or something. Then ill hide it all by pulling the carpet back over it.