Things You'll Need
Instructions
Download Q2toQ3A.exe and open the program.
Choose the following conversion options under each tab:
General - normal conversion
Lighting - Full Bright
Music - Uncheck
Skies - Blue
Click "OK."
Click "Convert" and choose the Quake 2 map you wish to convert. The program will ask for your "Quake 2" and "Quake 3" installation directories.
Save the file in your Quake 3 Arena directory with the naming convention "nameofmap"_q3.bsp, replacing the quoted text with the appropriate name of the map.