Tap Settings in the bottom-left of the main screen

Tap Account Center in the bottom-right

Tap this gear in the upper-left

Tap Personal Data Request at the top of the screen

Write down this pin, and tap the blue link

Enter your pin and submit

Expand FAQ number 5.

Tap this blue link

Scroll to the bottom

Check these boxes

Select a reason

Tap “Delete My Game Account”

Confirm

Tick

Continue

Done