Replacement Switch Joycon Wrist Strap SL&SR Buttons Zelda Skyward Sword Edition
 
 
The Legend Of Zelda Skyward Sword - Joy-con Wrist Strap
It is easy to replace
To apply, simply slide it into the appropriate joy con.
There should be a click and adjust to the most comfortable position.
On the bottom where the strap starts, press up to lock the strap in position.
To remove, press down the lock.
Slide up and out (might need a little wiggle)
Suitable for Nintendo Switch