How can I change the LifeWatch straps?

Helo LifeWatches are equipped with quick-release pins. Just slide the quick-release pin on the spring bar to retract it and remove the band. 

To put the band back in, slide the quick-release pin to retract it, align the spring bar with the opposite side of the device, and release the quick-release pin to secure the band once it is in place.

How can I manually measure the Stress Level on my LifeWatch Generation 2?