How do I make this image transparent

[Krikor]

There are several ways to get what you want.
Basically it's as described in Sallyanne's and PixLab's posts.
You will use Fuzzy Select and Color to Alpha as your main tools, selecting the desired colors and deleting them or copying and pasting them into a new layer.

I started by selecting the outer black color and then deleted it.
Then I selected all the remaining black color, copied it and pasted it into a new layer.
While the selection was still active, I deleted this selection, leaving only the colors that were not black.
I did the same for the white color (DANGANRONPA) - and placed this text on a new layer.
I left the blue text outline alone on one layer so I could adjust the opacity.

   

Having all the parts separated into layers is just a matter of placing your art on a layer at the bottom of the layer stack and making minimal adjustments.