You can easily update your name, mobile number, email address, and password associated with your account in the Careem app.
Go to Menu > Settings and tap on the info you want to edit.
You can also edit your profile on the web by signing in at www.careem.com.
Note that if you signed up through Facebook, you won't be able to change your password as you never set a password in the first place. If you want to set up a password, you can unlink your Careem account from Facebook.