I'm planning to donate a laptop to a school, for kids to use from home during the pandemic.
It's my previous work/development laptop, so I want to erase the drives as securely as possible (within reason, I'm not exactly expecting a state sponsored attack.). But keep them in good working order.
There's both an HDD and SSD drive, from what I gather these require different approaches.
What would be the recommended steps to wipe the drives?
Going for a security level to counter "A knowledgeable person with some freely available software".
And if it's not offtopic for this site, are there any recommendations for free or low cost tools?