Comment 1 for bug 1170604

that does not help

jevgtv@jevgtv-HP-Compaq-6910p ~ $ sudo modem-manager
[sudo] password for jevgtv:
modem-manager[8477]: <info> ModemManager (version 0.6.0.0) starting...
modem-manager[8477]: <warn> Could not acquire the org.freedesktop.ModemManager service as it is already taken. Return: 3
jevgtv@jevgtv-HP-Compaq-6910p ~ $ man kill
jevgtv@jevgtv-HP-Compaq-6910p ~ $ kill modem-manager
bash: kill: modem-manager: arguments must be process or job IDs
jevgtv@jevgtv-HP-Compaq-6910p ~ $ kill mm
bash: kill: mm: arguments must be process or job IDs
jevgtv@jevgtv-HP-Compaq-6910p ~ $ kill modemmanager
bash: kill: modemmanager: arguments must be process or job IDs
jevgtv@jevgtv-HP-Compaq-6910p ~ $ sudo killall modem-manager
jevgtv@jevgtv-HP-Compaq-6910p ~ $ sudo /etc/init.d/network-manager restart
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service network-manager restart

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the stop(8) and then start(8) utilities,
e.g. stop network-manager ; start network-manager. The restart(8) utility is also available.
network-manager stop/waiting
network-manager start/running, process 8605
jevgtv@jevgtv-HP-Compaq-6910p ~ $