Bicycle Mechanics - removing sprocket wheel

Hello,
I am trying to take the sprocket wheel off an old Spiegel Airman bicycle. I know I have to unscrew the pedal arms from each other, but I don't know if the threads are right or left handed. The nut opposite the sprocket wheel was left handed. Things are pretty rusted and I have turned really hard to separate the 2 sides, assuming it was right handed, but it wouldn't budge. I am wondering if the threads may be left handed.
thank you
Jim

I have to unscrew the pedal arms By arms, do you mean the crank or the actual pedal?

If just the pedal proper, yeah if the other was left hand threaded, the opposite side WILL be a right hand threaded.

A picture would be great if I'm still lost as to your question.

I'm probably not very good at the terminology. I mean the part that the sprocket wheel is attached to. Not the pedal. I'm pretty sure that where that part goes through the tubular hole in the frame there are threads that separate the two sides. On the opposite side of the frame there is a big nut and that was left handed and it came off. I want to take the spocket wheel off and I wonder if the threads where it goes across inside the frame are left handed.
thank you
Jim

Yes, on Ashtabula cranks everything on the left side has left-handed threading. Just remove the left pedal, the bottom bracket locknut, the washer, then unscrew the cone and remove the bearings. Once the left side is disassembled, you can just pull the crank out the right side. Just remember, everything on the left side is left handed, clockwise to remove.