If you are reading this, CONGRATULATIONS! You have taken your first step in to video game console modding! 
If modding consoles is illegal in your country, or you have even the slightest fear of death by electrocution, turn back now. :P

(Note: Depending on your preferred method, death by electrocution may only occur via modding of the Xbox)

Xbox Version:
• Follow the most convenient of the following guides to mod your Xbox:
  http://daleswanson.org/stuff/xbox.htm
  http://www.xbox-hq.com/html/xbox-tutorials-183.html
• Use C-Xbox Tool 2 to transfer default.xbe from the game folder to your PC and and open it in any hex editor.
  Search: 24500000 803FD84E
  Replace: 24500000 403FD84E
  
• Save and transfer the file back to the Xbox.

PS2 Version:
• Using Codebreaker 9.2 or higher, input the following code:
  2010c248 3c014370
  2010c088 3c013faa
  
• Alternatively, you can take the following data and save it as a .pnach file, then use PS2 Patch Engine to patch it directly to the ISO or run it through PCSX2:
  gametitle=Bionicle (NTSC-U) (SLUS-20818)
  comment=Widescreen hack by ElHecht

  // 16:9
  patch=1,EE,0010c248,word,3c014370 // 3c0143a0 hor fov
  patch=1,EE,0010c088,word,3c013faa // 3c013f80 hud fix

Gamecube Version:
• Don't bother using original hardware if you can help it. Gamecube homebrew is much easier run on the Wii.
  (Note: You need a pre-2009 Wii model with Gamecube hardware in order to do this)
• Download and install The Homebrew Channel: http://hbc.hackmii.com/
• Download and install Multi Mod Manager to your HBC: http://gbatemp.net/threads/mmm-multi-mod-manager-a-collection-of-tools.208281/
• Follow this guide to download and install WiiGator's cMIOS: http://www.wiihacks.com/recommended-faqs-guides-tutorials-only/47802-playing-gamecube-backups-disc.html
• Download and install SwissGC to your HBC: http://code.google.com/p/swiss-gc/ 
• Follow the menus and check "Force Widescreen" then launch.

PC Version (this one's a doozy):
• First, make a copy of BIONICLE.exe in the game's directory, keep it as a backup.
• Right-click the original BIONICLE.exe and select Properties, then go to Security.
• Click Edit and give all the groups and users full control, Apply and close.
• Open BIONICLE.exe in a hex editor, such as HxD: https://mh-nexus.de/en/hxd/
• Ctrl-F search for "BE9FAA3F", making sure to change Datatype to Hex Values if given the option.
• Replace "BE9FAA3F" with the following number corresponding to your monitor's native aspect ratio:
5:4			-	00 00 A0 3F
4:3			-	AB AA AA 3F
3:2			-	00 00 C0 3F
16:10		-	CD CC CC 3F
15:9		-	55 55 D5 3F
16:9		-	39 8E E3 3F
21:9		-	26 B4 17 40
Triple-monitor:
3x5:4		-	00 00 70 40
3x4:3		-	00 00 80 40
3x16:10		-	9A 99 99 40
3x15:9		-	00 00 A0 40
3x16:9		-	AB AA AA 40
• This changes the FOV of the game so it doesn't look squashed or stretched, as well as adjusting the menus to fit.
• Scroll back up to the top of the file and click on the first line to put the cursor back at the beginning. Now Ctrl-F search, again for Hex values, for "20030000".
• Press the F3 key twice to skip past a couple of instances that don't need changing.
• Figure out your monitor's 4:3 resolution. To do this, find its vertical resolution (such as 1080 for a 1080p monitor or 720 for 720p), divide it by 3 and times it by 4. Note that it does not matter how wide your monitor really is, just pretend it's 4:3 for now. Common resolutions are listed below:
Horizontal : Vertical
2880 : 2160
1920 : 1440
1440 : 1080
1024 : 768
960 : 720
• Now replace the "2003" part in the hex code with the hex value corresponding to your horizontal resolution. A full list of hex values for common resolutions is available here: https://www.wsgf.org/article/common-hex-values
• It's important to get horizontal resolution right, as the game will calculate the screen's vertical resolution based on it. Get it wrong and the game will display an unsupported resolution and you'll have a black screen.
• But if you've followed all the steps above, simply save your changes and run the game!
• Note that video sequences like the opening movie and company logos will ALWAYS display at their native resolution, no matter what you do here. That means you monitor may black-screen while switching video modes.