How do I change what the button does on my watch?

You can't.

 

I haven't seen the use of this as a dedicated button. I can see why they did it, but i have a feeling it isn't useful to a good chunk of people. Maybe they'll realize this at some point and allow changes to the defaults.

Only thing is there's no other way to get to the friend ring (that I've seen anyway), so they'd have to make an option to access it through a glance or app.

 

Would be awesome if you could change it but you can't.

 

The side button beneath the digital crown loads your friends as well as Apple pay. Friends allows easy access to call/text your closest friend, Girlfriend, Wife...etc. Double pressing side button enables Apple pay.

 

I have a feeling that in the fall when Watch OS2 comes out that this may change and the developers at least will be able to use it for other purposes.

 

The side button in combination with the digital crown are also used to do a hard reset when it gets confused and doesn't operate as expected (press and hold both for 10 seconds until the screen turns off and it reboots). So it actually already does perform several different functions.

Single press - friends access
Double press - Apple Pay
Press hold with crown - hard reset

 

The only time I have used that button was to reset my watch. I hope for some customisation here in WatchOS 2.

 

Or a quick press of both the crown and button at same time takes a screenshot of the Apple Watch screen which is saved to iPhone camera roll.

 

ME TOO, as I never initiate a call on my watch and would love to have this button to do as I wish. Right now I never use it as I do not use Apple Pay.

 

I have no friends, they need to change it ASAP

 

Hey, Siri, thesmokingsuns needs friends to add....please fix that.

Ahhh, I also added some of my phone favorites here. Like speed dial on the wrist.

 

I wish it could be changed. That button is completely pointless imo.