https://support.apple.com/en-us/HT202313
If you previously "purchased" Lion under your AppleID, you should be able to hold command-option-r at boot to get to Internet recovery. After startup with those keys held you will be asked to select your wifi, then you will be asked for your AppleID. After that you will see a spinning globe while the recovery utility downloads. Then you will see the recovery seen and from there you can use Disk Utility to format the drive to Mac OS Extended (Journaled) and install Lion.
After you get Lion in stalled you can use the App Store ti go back up to El Capitan if you want.
Purchase Lion from Apple for $19.99. You will receive an email with a content code for the download from the Mac App Store. Lion and above do not come on a disk.What do I do if I never purchased Lion with my AppleID? Do I need to get my hands on a physical disc???
You need to purchase it like CoastalOR described, but since your Mac is out of commission for now, you will need to do that from another Mac.What do I do if I never purchased Lion with my AppleID? Do I need to get my hands on a physical disc???
No... on any Mac when you do Internet recovery with command-option-r that will get you the OS X version that came from the factory. So if your Mac came from the factory with El Capitan, Internet recovery will get your El Capitan... otherwise no.I'm going to need to wipe my MBP and I want to reinstall the OS. When I "hold command-option-r at boot to get to Internet recovery. After startup with those keys held you will be asked to select your wifi, then you will be asked for your AppleID." When I enter my AppleID is it going to somehow know that I previously had El Capital on the MBP and redownload it?