those wiki articles should be your first stop. I wouldn't recommend making kernel configuration adjustments through xterminal if you don't have any experience using bash/busybox. In a nutshell:

a) install power-kernel through the repositories following those wiki links
b) install rootsh through the repositories following those wiki links
c) reboot and load a default kernel config through kernel-config load <kernel config here>
d) save the kernel config through kernel-config save <kernel config name here>
e) modify your newly created kernel config to your liking (min/max frequencies, scaling thresholds and sampling rates, even voltages if you so choose)
f) load your config through kernel-config load <your kernel config name here>
g) install conky from the repositories, watch conky and play a bunch of media, browse the web, perform a load of tasks to see how stable your device is at your new frequencies.
h) modify /etc/init.d/rcS to reflect more io pressure sanity.

Seem a bit daunting? The wiki links are there for a reason. cheers!