It's likely easier than you expect. Most Linux distros come with the ability to read and write to the same file system that Windows uses, so other partitions than your install partition can be carried over. This isn't ideal because the that FS has some issues, but it does function fine. I've still got a drive that's mostly media on that filesystem.
The biggest issue is if you depend heavily on particular pieces if software that don't have native Linux versions, though wine may be able to work around that and, if not, a virtual machine can likely handle it.
It's really not too big of an issue to switch. You've likely tinkered with Windows to make it not garbage than you'll have to do with Linux (though you have a lot of options to go further if you want).