Iphone/Itunes Syncing to New Computer?

[newyorkcity]

Is there any way to change the computer my iphone syncs to without resetting my phone? curerntly my iphone syncs to my Mac Pro but if I move my Itunes files to an external can I sync it to my Macbook Pro? I would really like to sync to both if possible, but if this is not an option how do I change the computer my iphone syncs to, to my Macbook Pro?

 

[Apple06]

This is what I've followed recently on my new Mac Mini with Mavericks and iTunes 12.01, coming from a 2006 MacBook with Snow Leopard.

http://www.macworld.co.uk/how-to/mac-software/how-sync-iphone-itunes-without-erasing-content-3523862/

It didn't erase my iPhone content but I've had to re-select everything except Apps and did a sync.