Spotlight cable through tranmission resistor metal plate in firewall - HOW TO REMOVE?

Hi all.
Im trying to feed cabling from new spotlight wiring harness through into the dash through the firewall through the metal plate that holds the transmission resister. Ive unbolted it etc and it doesnt budge... Im assuming there is some adhesive holding it down. I want to drill a hole in and place a grommet so i can pass the cables through as shown in the pic i stole off another thread. The only way I think I can make space is to remove the fuel filter so i can get a drill in there.

Any advice would help.

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