Disclaimer: Remember to scan any files you download for viruses before opening or running them.
Patching the ROM
Your ROM needs to be in native (big-endian) format. Use the file hash in the patch’s readme to verify you have the version and format.
Check this post for more information on file hashes.
Click Apply Patch. This will create a second file Densha de Go! 64 (Japan)PATCHED.z64 in the same directory as the ROM.
If you’re using Project64 and getting a “Fatal Error: Stopping emulation” error you’ll need to change a few settings.
Open the ROM and click OK on both errors. Go to Options > Configuration.
Select Config: <ROM name> and change Memory size to 8MB.
Click OK to save settings and open the ROM again.