I think the basic principles apply to an atmega 1280 or atmega 2560
if it is a arduino board, it has a icsp connector you can use
if not - look in the datasheet to find out what pins to connecto to 5v, gnd, miso, mosi, clk, and off course reset
and off course connect a crystal
maybe post pictures, more information if the target is a bare ic or a board, will get you some more help ?