MuayThaiJayIf you're going from the stock NATO strap to another NATO strap, you don't need any tools. If you're planning to go rubber, leather, or silicone standard bracelet style strap, you'll need a spring bar tool.
http://www.crownandbuckle.com/index.php/how-to
Yoshiod9I really meant to ask when I remove the strap that this wacth comes with, will I need a tool to put on the replacement NATO 5 metal ring nylon 22 mm replacement band?
MuayThaiJayNo, NATO straps just slip through one lug, under the watch, and up through the other lug, then you pop the end of the strap through the other bit with the ring(s) at the end.
Also, you don't need a spring bar tool for this watch, you can just poke a paperclip through the holes on the outside of the lug to compress the spring bar.