This function deletes the window or dialog procedure that was previously loaded using the WinLoadProcedure function.

#define INCL_WINLOAD /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HAB      hab;       /*  Anchor-block handle. */
PFNWP    pwndproc;  /*  Window procedure identifier to be deleted. */
BOOL     rc;        /*  Procedure-deleted indicator. */

rc = WinDeleteProcedure(hab, pwndproc);