Add enough links after your circuit for your bracelet to fit your wrist. Peel off the paper backing from the motor and stick it in between layers of material.
Put some black tape or heat shrink tubing around your battery and plug it in. Wind the wire through the bracelet and tuck the battery between the layers of material. Loop the closure tab through the last link and wear it!
Your bracelet is not waterproof! You can take steps to ruggedize your circuit to make it more splash resistant, if that's your thing.
You can customize your bracelet's vibration by changing up the Arduino code. Maybe try using PWM to give the vibration more nuance or create different buzz patterns for different spans of time passed-- how would you make this project your own?