it is fairly easy to do, use the tool and unscrew the shaft then you can take it out and replace it. be careful not to force the shaft as they are somewhat delicate. but with a few trial runs you should get it down easy.

Hi Bart - 

Titleist did not release an AP2 2iron.  There is a 2 iron available in the CB only.  

Hi Joe - 

It is certainly possible for a set of irons to be stamped with different serial numbers.  The serial number is generated at the time the order is entered.  So if the 4iron and GW in your set were ordered at a different time they would be stamped…