2010 laptop cleaning to donate

So a friend of mine has tasked me with cleaning off a 2010 Macbook (white) to donate to his church. It was his moms computer and of course is full of garbage stuff they don't want to give it to the church in this condition and they don't have the original disks.

Now, it came to me with Snow Leopard installed and I borrowed an install disk (full retail white label) but the computer kernal panics as it loads from this DVD. I have heard someones theory that the Macbook came with 10.6.8 and the install is 10.6.0 so maybe it's a issue.

Is there any other way to clean off everything back to new without the original disk (and no I am not spending many hours trying to delete every file, download, song, pref that it has on it by hand.

Thanks for any help. I only have the Snow Leopard disc for a few days so hoping to solve this quickly