- Close Chrome and locate your shortcut to Chrome. Optionally, locate the Chrome.exe file itself, and create a shortcut.
- Right-click the shortcut, and select 'Properties'.
- Go to the 'Shortcut' tab.
- In the 'Target' line, there will be something like 'C:\Users\equex\AppData\Local\Google\Chrome\Application\chrome.exe'
- Append after that text in double quotes: --disk-cache-dir="your_drive:\your_folder". This will only move your cache files, which is good enough.
- If you wanted to move your complete Chrome user-folder, append --disk-user-dir="your_drive:\your_folder", and then copy the contents of the old folder into the new one before you start Chrome again.
- Click 'Apply' and start Chrome. To verify, look inside your new folder and observe Chrome creating temporary files.
There's a guide for FireFox here.