Initial check
user@host> request system snapshot
user@host> request system snapshot media internal
Installing image
user@host> request system software add [package location]/[package name] reboot
user@host>request system software add "ftp://test.jnpr.net/pub/junos/7.5R2.8/jinstall-7.5R2.8-domestic-signed.tgz reboot
user@host>request system software add /var/tmp/7.5R2.8/jinstall-7.5R2.8-domestic-signed.tgz reboot
Other options
user@host>request system software add /var/tmp/7.5R2.8/jinstall-7.5R2.8-domestic-signed.tgz no-validate no-copy reboot
Installing step by step
user@host>file copy ftp://username:prompt@ftp.hostname.net/filename /var/tmp/
user@host> request system software add /var/tmp/jinstall-8.x-package-name-signed.tgz
user@host> request system reboot
Primary and backup copy to be the same
user@host> request system snapshot slice alternate