Quoted from RCA1:It would be slightly more work to crimp the terminals, and you would need a crimping tool.
Either way, he'd need to buy a tool. The slightly longer time it would take to switch to a Molex type connector is worth it. Easier to learn crimping Molex edge connectors than it is to use an IDC insertion tool.
Quoted from eman4277:Is the 18-20 AWG correct?
Yes. Click on the related parts link on that page for links to crimp tool and housings. Header pins on board may not need to be replaced. Remove the burnt female connector (the burnt end may fall apart) and inspect the pins on the board. Wipe pins with alcohol and if any still look dark or burnt, header pins should be replaced.