Is it possible to do w/o serial cable(do not have one).
No
It's easy, belive me, in no way I'm good at soldering but I managed to do it right. The serial cable is an USB to TTL and I think you can find it easily from the internet for cheap. Then for the connections you just need to find out the RX and the TX headers and the ground. Connect RX with RX and TX with TX. Don't connect the 5V.