johnneyw,
The demolition debris is being removed via the subway that links all of the platform buildings and then taken to the old GPO▸ (Government Printing Office, or possibly General Post Office - now referred to POT▸ (Post Office Telecommunications) - depending on context) site where it is sorted and transferred to skips for disposal.
As for the canopies, they are not being reinstated to their former length but the exposed gables will have dagger boards fixed to them.