So i have burned arduino serial chip and i bought something for his replacement. Its on the link below
I think i know how to use it, but i need some help with the details
UART 2 Board to Arduino Uno R2
RX -----> TX (Pin1)
TX -----> Rx (Pin2)
5v -----> Vin
GND -----> GND
RTS -----> ????
CTS -----> ????
Now what to do with the RTS and the CTS pins?
And what do these pins do ?
And will this work ? 
RTS -----> RESET
CTS -----> GND
If it'll work, well it depends on how burned your arduino might be =)
If you haven't brought it already, you can use this: http://www.ebay.com/itm/190685792376?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2648 it's cheaper =)
Not totally burned 
, when i plug in usb ( in to the original port ) i get power and the last code that was uploaded to the AtMega is running but i cant upload a new one and the pc doesn't detect the Arduino.
Now i dont understand what the RTS/CTS (Request to Send / Clear to Send) pins stand for and therefor i dont know how to use them :~
Why are you suggesting RTS -----> RESET , CTS -----> GND?
Some say i need to put RTS -----> CTS...
On an FTDI you have CTS pin, which is connected to GND (in some cases, for example in the FTDI itself you don't need to connect it because it's internally connected, but i don't know about that one)
RTS -----> RESET (Because you need to reset the IC before flashing it)
Also i'm sorry i forgot but you need 0.1uF capacitor in between.
RTS -----> RESET
No - Use DTR to DTR, which goes thru a 0.1uF cap to Reset.
I use them all the time:
http://www.crossroadsfencing.com/BobuinoRev17/
