maybe wear a 3"dia x 1/16" thick 'whizzer' cut-off wheel down to 1"dia then see if it'l fit inside the race to cut it..mount it up in a pneumatic die grinder..if you use the torch soak down some old towels with water and wrap them around the clutch first.Maybe even immerse it in water when you cut it..that'd hold temps down for sure

here's one- sunstar clutch

best of luck,sometimes these small jobs are nut-kickers..been there