Cutting / Triming Stereo surround

[1200det]

I need to enlarge a Stereo surround in a hilux about 2-3cms all around the surround

Im after the best option for cutting plastic and getting a nice smooth result ?

Example picture (This looks rough how he has cut / enlarged the surround)





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[RA35GT]

Carefully mark out where you want to cut the plastic, then either use a dremel or hacksaw to cut on the waste side of the line. Make sure the cut is as straight as possible.
Then hand file the rest of the way. (Using a wide flat file at an angle helps to keep it fairly straight).

You can remove a lot of plastic in a short amount of time when filing so make sure you keep an eye on the line ! (Check often!)

I think too much material has been removed from the pics above.

The stereo (if new) should of come with an "installation cage" thing. Use that for your template on the size of hole to cut/enlarge to.