Plastic Mod ?

I was browsing Amazon, trying to find something like a hot knife tool to cut/melt plastic. I have a Dremel tool, but they like to jump around to much sometimes. Since I am doing my next mod on the plastic bumper black out area, I want to be precise.

There are some that are for styrofoam. Using a wire to cut, like a wire cheese slicer. Those won't work unless cutting from the edge. I need something to cut out a hole. Is there something out there that fits the bill?

Thx

 

WINONS Hot Knife Plastic Cutter Tool, Multipurpose Stencil Cutter WHK-0005 (Kit of 18)

$16 WINONS Hot Knife Cutting Tool, WHK0005 Plastic Cutter also Effective for Foam Board and Stencil (Kit of 19)

https://www.amazon.com/dp/B0865RDNZ3/ref=cm_sw_r_cp_api_i_HkNHFbTBKTGBF

Or if you already have a soldering iron they make generic knife tips to replace