If you don't know how to edit you may want to rethink editing it as it can cause problems if you mess up. But if you want to, just open Terminal and enter the following.
Another handy tip for the command line is the more command, which lets your view documents like .bashrc without opening an editor. Obviously, you must open it in a text editor to actually change anything.
$ [COLOR="Blue"]pico foo[/COLOR]
GNU [COLOR="Magenta"][B][SIZE="3"]nano[/SIZE][/B][/COLOR] 2.0.1[SIZE="1"] File: foo
_
[ New File ]
^G Get Help ^O WriteOut ^R Read File^Y Prev Page^K Cut Text ^C Cur Pos
^X Exit ^J Justify ^W Where Is ^V Next Page^U UnCut Tex^T To Spell
[/SIZE]