How Do I Clean My Budgie's Vent?

I've just noticed that my budgie's vent is dirty and covered in poop. I did some research and most posts/sites advised me to clean his vent (obviously), but they didn't seem to specify how. This, along with any additional advice/information would be massively appreciated  

For background information, he doesn't like people touching him or getting close to him in any way and only comes to me when he wants to (usually to sit on my head/laptop). So getting him to "agree" to me cleaning his vent will be the first and most difficult challenge I assume.