How to sign out a Apple ID without the password?

You need the password if it asks for one.

Click on this link to read what to do "If you forgot your Apple ID password" --> https://support.apple.com/HT201487

or go directly to this link --> http://iforgot.apple.com/

If you didn't receive your verification or reset email click here --> https://support.apple.com/HT201455

If you are being sent a verification code to a phone number to which you no longer have access, click on the next link to see the various ways of getting a verification code:

Get a verification code and sign in with two-factor authentication --> https://support.apple.com/HT204974

If you still need help:

Contact Apple for help with Apple ID account security "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues." --> https://support.apple.com/HT204169

Also read about "What to do after [or before] you change your Apple ID email address or password" --> https://support.apple.com/HT204071