Chosen Solution
My MacBook is running Mojave and I need to instal El Capitan on my iMac (what was on it before I needed to replace a bad hard drive). I can’t get it to download using my MacBook through legitimate Apple sources. HELP! That link Aaron provided is from Apple and since I am running Mojave I can’t download it.
Depending on the age of your iMac you should be able to install your new SSD into your system and then run the Internet restore using the start up keys: Command (⌘) & R keys Reference: About macOS Recovery To gain access to the older macOS’s use the startup keys Shift & Option-⌘ & R keys Reference: Reinstall from macOS Recovery
