Typically you would put an ICSP header on your board. Then you would use Sketch->Upload Using Programmer to upload the sketch to the chip. I recommend the "USBasp" for ICSP programming. They are very inexpensive on eBay.
Typically you would put an ICSP header on your board. Then you would use Sketch->Upload Using Programmer to upload the sketch to the chip. I recommend the "USBasp" for ICSP programming. They are very inexpensive on eBay.