You need adb for this only if you have (if I remember correctly) 2.xxx rom which don't allow you to enter bootloader mode by pressing Camera+Power. But in any case it is better to install adb (Comes with Android SDK) and usb drivers. Also Liquid-specific drivers must be installed. (Can be found from Drivers-thread at top of the forum)
"fastboot" which is mentioned at parts 5. and 6. is windows executable. You can get this by downloading Paul's Superboot. That file is named superboot-windows.exe in that package.
So put this downloaded rom and modified superboot in same folder with superboot-windows.exe and also all dll-files in Paul's Superboot package, install usb drivers, enter into bootloader mode.
After that run windows command prompt (Win-button + R --> cmd --> ok), navigate to folder where you have put all those files and then follow instructions at parts 5.-.7.
Hope this helps. If you have problems PM me in Finnish and I can help you out. =)