SIM800 libary with SoftwareSerial

How can I use stanleyhuangyc sim800 library with softwareserial
https://github.com/stanleyhuangyc/Freematics/tree/master/libraries/SIM800

I use this bord from seeedstudio, the sim800 is connected to pin D7 and D8
http://www.seeedstudio.com/depot/Seeeduino-GPRS-p-1909.html?cPath=6_7

SIM800.h

// change this to the serial UART which SIM800 is attached to
#define SIM_SERIAL Serial1

I downloaded the SoftwareSerial library and copy it to the sim800 library, otherwise the compiler could find the files
This does not work

#include <Arduino.h>
#include <SoftwareSerial.h>
SoftwareSerial mySerial(8, 7); 

// change this to the serial UART which SIM800 is attached to
#define SIM_SERIAL mySerial

I get this error
several definitions of “mySerial”

Any news about this? I have the same problem.

No

I try to use AT commands without library

Same problem. Will try to copy the library to the sketch...