How to stop attached USB device / send IRP_MN_REMOVE_DEVICE?

[Sven Hazejager]

Hi all,

Is there a tool under FreeBSD 6.2 that properly stops a USB device, 
equivalent to Windows XPs Safely Remove Hardware? I noticed that Windows 
sends a IRP_MN_REMOVE_DEVICE command, after which my LaCie external HDD 
spins down. I would like to do this under FreeBSD too.

So, the question really is: how to send a IRP_MN_REMOVE_DEVICE command?

Thanks,

Sven