That is a 'zipped tarball' - meaning you do the following, in order, no skipping steps:
- Copy file to root of your SDCard (It has to be named either {name}.rom.tar or {name}.rom.tgz)
- Reboot into recovery
- --> Install
- --> Select ROM
- Select it
- It will start by making a Nandroid backup
- It then asks you to select voltage type - Low Voltage, Medium Voltage, High Voltage. Pick one (remember, Adam said start with lowest first)
- Then you pick which kernel you want from the list presented.
- Then it installs, and you reboot.
Word of advice - if you already have SetCPU installed and have set up profiles for the default kernel, change it so that it is either disabled on boot, or else (better way) change all max settings to 550 / 600
before you start to play with these kernels, and if you don't like a kernel that you install, after changing SetCPU back to your preference,
change SetCPU back as I just mentioned each and every time before flashing to a new kernel.
Yes, this is a
lot of work - but it is a lot easier than downloading one boot.img file, booting into recovery, updating, testing, dismissing it, then having to repeat that entire cycle.
This way, you have all kernels accessible to you at any given moment.
HTH