Reset Office 365 User Password with PowerShell

Connect-MgGraph -Scopes "User.ReadWrite.All", "Directory.AccessAsUser.All"

$UserId = "user@acmecorp.com"
$NewPassword = "theN3Wp@ssword"

$params = @{
    PasswordProfile = @{
        ForceChangePasswordNextSignIn = $true
        Password = $NewPassword
    }
}

Update-MgUser -UserId $UserId -BodyParameter $params