This week I received an iMac 27" late 2009 that doesn't have internet recovery and I had to reinstall OS X without original Apple ID.
First step is to download a compatible OS X installation file on a working Mac computer and then create a bootable flash drive.
The OS X can be downloaded from this loation and also follow the instruction of creating a bootable media.
In my case I had to download and install OS X El Capitan and I had tho use the following command in Terminal to create the bootable flash drive.
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app
After entering the command you will have to enter the computer password and press Y key to confirm that you want to erase the flash drive.
When you see "done" message in terminal, the flash drive is ready and can be removed from the computer.
Next step is to connect the drive to the iMac late 2009 and boot from it by pressing options at startup. Select the newly created flash drive and install the operating system.