Imporint sprites without proper alpha channel

I'm working on making a small portion of a Zelda remake in Unity as a personal project. I've found some great sprites for Link here: https://www.spriters-resource.com/nes/legendofzelda/sheet/8366/ However, when I load this into Unity and select the sprites using the sprite editor, Link has a gray box around him. Now, I could change this via a script but doing so makes it difficult to work with for animations and all that because I'd have to somehow fix it every time.

What I want to understand is: How can I load in the sprites in a way that makes the gray box the transparent color? Is there a way to do that? If not, what's the best approach to dealing with this? Do I need to edit the image somehow?

Thanks!

 

open the sprites in photoshop and delete the background, then save as .png and drag it into unity.

 

Thanks for the response! I could do that. I am hoping to find a less manually intensive method.

 

its 3 clicks to do this btw, it takes literaly 3 seconds to do. here you go

 

Haha, well, thanks! I don't have photoshop nor have I used it much. What 3 clicks did you do?

 

magic wand, shift magic wand, ctrl x, ctrl s