My question is different to How can I reset to the factory settings? hence why I have posted.
The problem I am facing is that I have a Raspberry B+ which I have had for about 2 years. I didn't use it for a year and recently just did an upgrade from Jessie to the latest OS and things are working fine. I did, however, previously use it to try out different things and installed things such as OSSEC, Hadoop and other chunky software which I no longer have use for. I have uninstalled said stuff, did a purge etc, but I feel like a clean start would be the best going forward.
Is there a way to reset the Pi without flashing the SD card. The Pi is currently running headless and operated via SSH but I am able to hook it up to a mouse, keyboard and TV if needed. What I can't however do is format an SD card or flash a new OS as the SD card slot on my Mac is currently occupied with a memory card that is very difficult to remove and usually causes issues when I remove. I am trying to very much avoid this option.
I have looked at buying a USB SD card reader but as I only need it for this one job, not really looking to fork out that £.
Is there a way I can 'wipe' or reset the Pi into a clean install? I have researched around the topic, but I can't see an answer where someone says specifically that this is possible or isn't possible.
So again, how do I 'reset' to factory settings and start again without flashing the SD card. The Pi and current OS works fine and there is no issues with the hardware or SD card.