Using two pressure sensors with same address over I2C
For the hardware part, look at page 6 of the datasheet and move the resistor at the 0x76 label to the 0x77 position on one of the sensors.


  Does anybody know how I could extend the current example code provided
  to give two pressure readings?


If you're using the library linked to from SparkFun, have a look at line #39 of the code:

MS5803 sensor(ADDRESS_HIGH);


This declares and initializes a sensor object for the "high" address 0x76 and makes it available via a variable named sensor.

Then you can operate the sensor like

sensor.getPressure(ADC_4096);


So all you'd have to do is to set up another sensor object like

MS5803 myOtherSensor(ADDRESS_LOW);


and use it like

myOtherSensor.getPressure(ADC_4096);


to query data from the other sensor (the one with 0x77 ("low" address)).