As you might have noticed, we need a bit more information to help you.
On what stage of the gerber export do you experience your problems?
- Can you open your project in pcb new or do you get an error there?
- Do you have problems finding the gerber export tool?
- Hint in kicad 4 it is in pcb_new under File->plot
- Do you have questions about the settings in the plot dialog?
- Are you able to get gerber files but they are not what you expect?
- If this is your problem, explain what you expect and highlight what you got exported.
- Do you get an error message at any stage?
- If so give the detailed error message and also give us the information when you encounter the message.
- Did you already export the gerbers but viewing them in a gerber viewer shows some problems?
- Have you already send your gerbers to your manufacturer but he has problems opening them?
Please also state which version of kicad you use and under which version of kicad the original project has been designed.