Change the blue shades to white shades

I have an image of many different colors. I want to turn anything that is predominantly blue into being predominantly white, while leaving the other colors unchanged.

So if the RGB of the image has a great B than R and G combined, I want to set the B to 0, then invert the color. If the B is not greater than the R and G combined, I do not want to do anything with this pixel.

I want to do this with every pixel using Gimp. Is this possible?

Example:

Pixel is 234 R, 244 B, 55 G.  Do nothing.
Pixel is 42 R, 220 B, 32 G.  Change B to 0, then invert the RBG for that pixel.