I'd think about using a penetrating oil along with some moderate heat. Even a hair dryer. I'd do three or four circuits a few hours apart. Oil, heat, removal attempt. I've removed freewheels that way. A bit of heat will expand the parts, including the gap between the threads, and it seems to improve the penetrant's effect. (Assuming alloy expands more than a steel pedal spindle.)
Last edited by Anicius; 11-23-22 at 09:15 AM.