a) In the Homebrew Channel load cIOS38-rev19 Installer.
b) Choose IOS36 and press A and then choose what base to install. There are a few choices you can use. Using Base 38 is the default normal way and will let you play all games properly. The choice i will be telling you to make is IOS 37 as a base as it helps with USB and problematic games (for example Monster Hunter Tri and Guitar Hero 5 etc).
c) Ok so select IOS37 v3869
d) Choose Network Install (requires wi-fi) and press A.
After a few minutes it will show it has installed correctly.
When you install the cIOS as base 37, you will lose the option to use wad manager as this requires IOS 38 as the base. You can either just re-install cIOS 249 as base 38 so you can use wad manager and change it back when you need to play any problematic game or you can literally and this is the obvious and most simple way to still use Wad Manager...