I was searching the same question as above, forget all the above!!!
You can use any arduino as an ISP to bootload the smd 328p-au at 5volt and 16mhz. (I used the arduino uno)
1. Upload the sketch Arduino as ISP.
2. Get the right connections of mosi, miso, sck, reset
3. Choose in the board menu: Arduino Mini w/ ATmega328
If you get an error, your connections are bad.