If you already noticed the bleeders were spinning without coming loose it may be too late.
Be careful with the heat, especially around the rubber components. I sometimes use transmission fluid mixed 50/50 with acetone as a home brew, for me it works better than commercial penetrating oils at removing rusted nuts and bolts. A little heat can help after the bleeders have soaked overnight or at least a few hours if there is a time crunch..
Good luck
