As Christopher said, you can delete the assembly by simply deleting the assembly directory on the main server inside the job directory.
However, if you open the page again, the assembly data will again be flushed to disk. This way, you either close Hudson first, or go to the Hudson management console and "Reboot configuration from disk", which basically discards everything in memory and reloads from your configuration files.
Just make sure you do this right after deleting the folder.
Francisco passos
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