Provided the picture on amazon is correct then this monitor has a headphone OUTPUT socket (+ A 3.5mm INPUT for VGA)
All you simply need to do is connect your speakers to the headphone socket and then whatever source you have selected on the monitor will output the audio to your external speakers via the headphone jack.
**edit**
Just did a check on the speakers you want to use, your link doesn't work but I extracted the B002KQ561U product code.
This appears to be USB speakers, unless they also have an analogue input like a 3.5mm (headphone) then they won't work. You need speakers that have an analogue input, ideally 3.5mm otherwise you will need to build your own lead or buy adapters from ebay (dirt cheap £1 or so)