This edits the game's initial boot file, so you might make a copy just in case. Then again, you're only adding one line of code ...

Edit the config.ini file in the game directory, open it with Notepad.exe and add the following text to the end:

bindc+DIK_GRAVE(console_showhide)

This enables the console. While in the game press the TILDE key and input these codes (unverified):

sv_cheats 1 ... This enables cheats
game_godmode 1
suicide
g_developer 1
cl_showinfo 1
g_fly 1
g_noclip 1
map mapname