I am gonna tell you how to change or reset your password but before this you should know that you cannot change gmail password in gmail app so you have to switch to your pc or laptop for this, below are the simple steps tp change your password:-
1. Open Gmail in a web browser.
2. Sign in.
3. Click the gear.
6. Click Change password.
7. Verify your current password.
8. Type a new password.
9. Type it again to confirm.
10. Click Change Password.
1. Open Gmail in a web browser.
2. Sign in.
3. Click the gear.
4. Click Settings.
5. Click Accounts and Import.
6. Click Change password.
7. Verify your current password.
8. Type a new password.
9. Type it again to confirm.
10. Click Change Password.
It is done now.