Either replace the fuel lines with new ones or you can go down to the auto parts store and get the compressed fittings to splice the lines
I have a 1993 Ford F150 that has dual tanks. I use the back tank 99% of the time. I recently repaired a pin hole leak on the front tank and put everything back together. However, now it is leaking fuel from the fuel lines leading into that front tank. I was wondering how can I fix this leak?