How to sell my laptop?

[TangledThornz]

I have a gaming laptop that I hadn't used in over a year because I mostly game on my PC and don't travel anymore so I'm looking at selling it now while it still has value. My concern is the data on it and the best way to delete data off it while keeping the OS or should I just format the HDD altogether and tell the buyer to install their own OS?

 

[TangledThornz]

I was able to Google-fu my answer. This thread can be deleted,