Open the Instagram app or go to https://www.instagram.com/
Log in to your account
Go to your profile
Tap/click the menu (three lines) or your profile settings
Select Settings and privacy
Choose Accounts Center
Select Personal details
Choose Account ownership and control
Select Deactivation or Deletion
Select Deactivate account
Choose a reason
Re-enter your password when prompted
Tap/click Deactivate
Confirm when asked