Yup

Block the front wheels....Jack up the rear and support the chassis well

NO CINDER BLOCKS!!!

Put the truck in gear.....Start the truck.....push the peddle in and out several times....Try to change gear.....if it grinds turn off the motor and repeat the first stuff......Push the clutch in an goose the motor a little Use the brakes a touch ...whatever feels like it's working
This should free the plate......but It may not be good and need a new disc and flywheel surface anyway....

Good Luck