Its a 2 minute job with a dremel tool, just today I hade to trim out 1.5 inches of my 93 acrylic tank top to fit an HOB properly which is 10 times more touchy then glass tank trim. You can also use a hot knife blade and burn cut it. About 1/8 inch should be all you have to trim out.
If you can cut paper or cut your own nails, you can do that job as well just go slow and careful.