Hi! I bought HWL on itch a while back, but I didn't buy the guide at that time. I'd like to buy it now but I don't want to pay for the whole game twice just to get the guide. I'm worried If i buy it on steam, I'll also need to pay for the base game there to open it. Would it be possible to buy the guide separately somehow ? 

Hey! Thanks for your support!

It is a separate thing, but if you bought the game on itch, it should have come with a Steam key anyway. You can then activate it and you shouldn’t have any issues opening the DLC guide from there. If that doesn’t work for some reason, let me know and we’ll explore other options.