Subwoofer port roundover restricts airflow

Hello everyone,
I've recently bought a Gale Storm 8 powered subwoofer. Even excluding the wall thickness (or should I say thinness?), which is less than 1/2'', it also has a nasty plastic roundover end (flare) on the port, which instead of going in line with the port is actually glued inside the port, so air has to squeeze through a smaller, sharper hole when it exits the port. The first solution I had thought of is sanding the plastic bit inside the port, so the port will still be getting thinner in diameter when the air exits out, but it will atleast not have the sharp edges. The second solution is riskier - trying to pry out the flare, but it might break the wall and / or a port aswell. Anyone tried any of the two solutions and got any success? The subwoofer itself plays 40hz flat, 35hz f3, so it's not too bad for a cheapo 8 incher. Thank you!

P.S. Here are attached photos of the flare that I'm talking about: