Hey guys I'm coming along good on my 1/48Th ac-47 (and ill be posting pics soon hopefully) anyway i need to know how to cut these pieces WITHOUT a dremel, pics 1 and 3 are the same part, wow i need to redo that extinguisher
ive cricled the parts that need to be cut thanks guys

Do like G says, many passes with the hobby knife. Dremel tools are great but they also take alot of plastic with them, therefore, doesnt work for everything.

Dremels are not real useful on styrene, much more so on resin and metal. Plastic tends to melt at those tool speeds.
I like razor saws more. The ones made by Zona are inexpensive but durable.

I have a set of three that I've used forever. The Xacto saw has a flaw in that the tang that fits into the handle is folded over sheet metal, and it'll bend on you under force.
The many-hole method is a good one for openings.
In every case, if you don't need both halves of what you cut into, always cut away from the final edge at least a 1/16" and finish to the line on a flat piece of sandpaper taped down on a flat surface, or with a file in an opening.
After splicing together many a train car and a few fuselages, I've figured out the following:
put a piece of tape on the part with the edge at the final edge line of where you need to cut to, with the tape itself over the "keeper" side. Spray the piece with contrasting paint like black and remove the tape. Cut it apart well into the black; the 1/16". Then sand away until all of the black plastic disappears.
Sorry to go on so long, but sandpaper is much more forgiving that a saw, and a Dremel mistake is a real bummer.

I have a Bare metal foil scriber and thats a beauty for cutting open panels. Otherwise id chain drill it and then file it square,
Good luck,
...Guy