Upgrade Now Button does not show when upgrading to 4.6.9
If you disable the verify SSL certs and Force SSL certs before doing the upgrade (even if your site is on SSL) then the upgrade works fine. 

So in the upgrade process before turning of CiviCRM additional modules disable the two fields of Verify SSL certs and Force SSL certs. You can find the settings under /civicrm/admin/setting/url?reset=1

Remember to turn them back on. 

Cheers.