Phone [Q] Flash update.zip with fastboot or adb

I'm trying to flash something a update.zip package that contains su and busybox programs, and I know what you think, I'm rooting a device.
I've googled and there's the adb shell and fastboot programs that can help me but, how can flash it by commands?
Copy pasting the updater-script commands and the busybox installer too?
Please help me out! D:
Can I get legal issues if I name a custom ROM like "Jelly Beans (sweetened with Splenda)"? Serious question. D:

Moto G (Stock KitKat 4.4.2)
Xperia Sola (Paranoid Android 1.6 - 4.0.4 ICS)

Currently busy because of college works and stuff, so I afk, sorry folks.