[Random Dude]

[Edit] As to why they claim you only have 255 bytes? I don't know. There appears to be nothing in there at all. And I can write to bytes >0xFF so not really sure
[/edit]

This should suit you needs:

unsigned char readEE(unsigned char addrH,unsigned char addrL)  {
  	EEADRH = addrH;
 	EEADR =addrL;

    	  
  	EECON1bits.EEPGD =0;
  	EECON1bits.CFGS =0;
  	EECON1bits.RD =1;


    	return EEDATA;
}

void writeEE(unsigned char addrH,unsigned char addrL,unsigned char data)
{
  	EEADRH = addrH;
  	EEADR =addrL;
  	EEDATA = data;

  	  	//following as per spec. sheet
  	EECON1bits.EEPGD =0;
  	EECON1bits.CFGS =0;
  	EECON1bits.WREN =1; 
 	INTCONbits.GIE = 0;
  	EECON2 = 0x55;
  	EECON2 = 0xAA; 
 	EECON1bits.WR = 1;
  	INTCONbits.GIE = 1;
  	EECON1bits.WREN = 0;
}