How to program an Arduino Pro Mini with arduino UNO
In this video you can see the way you can program an Arduino Pro Mini using and Arduino UNO (or any other model of Arduino family). In this case, i've used a 5 to 3,3V bidireccional voltage converter, placed in the left side of the Pro Mini.
You only need to wire Tx and Rx signals between both boards (through the converter if necessary). Note that the micro is removed from the Arduino UNO board.
Actually, what I'm doing is replacing the micro that I've removed from the UNO with the Pro Mini.
Before I could do this, I have uploaded the bootloader to the Pro Mini because this board haven't it loaded from factory (using the same Arduino UNO as programmer and the SPI interface).
Please, apologize for the quality.