Minha resposta é citada de esta pergunta do stackoverflow
The fastest and easiest way to get "new identity" is send HUP signal.
Tor daemon re-read configurations files and make "new identity".
I keep special bash script for this:
# cat /usr/local/bin/nym
#!/bin/bash
pidof tor | xargs sudo kill -HUP
My sudoers file full of NOPASSWD:
# cat /etc/sudoers
....
anonymous ALL=(ALL) NOPASSWD: ALL
...