It is very easy to replace them. Just www.youtube.com it. If you are unsure we can proof view it for you.

 

Just an update. After listening for awhile it sounds like it does it a little in 2wd too I'm just going to sign it off as tire waer differences for now. If it gets worse I'll have it looked into. Everything seems okay underneath, took the cv joint boots off, looked fine. So it seems it's nothing to worry about

 

I'd still take it in and have it looked at. You had/have a noise and don't know what it is and it would be worse to put it off til something big goes wrong and it costs an arm and a leg. Proper maintenance is the key.