For the safety of your Instagram account, it’s better to change your password from time to time.
That’s why we explain below how you can easily modify your password using the iPhone app:
 1  Open the Instagram app
and click on the profile icon on the bottom of the menu.
 2  Edit your profile
is a button you’ll find on top of the screen.
 3  Change password >
is an option you’ll notice below Account.
 4  Enter your current password
followed by 2 times the new password that you want.
 5  Click on Save
It becomes available in the right top corner.
 ✓ Result
You have now modified the password of your account.
Source screenshots (& thanks to): Instagram app