WANT Cool medium brown. HAVE bla brown with Green

So I added a Neutral medium brown to my bleached blond hair, and yes, it's uneven and green   

In a perfect world, I would have a pretty cool medium brown all over color. So, my question is, what's the best way to get there? Here is what I've come up with after getting lost for 3 hours online :)

1. Apply a medium red all over, then apply the cool brown.
       Should I use a protein filler?

2. Apply a Neutral protein filler, then color with a warm medium brown for a while, switching to cool tones a couple of months down the road.

3 Use a colored protein filler, then color with desired cool brown. But what color filler? I know they have red (which is the tone i need to cancel out the green) Or the brown, which is my end desire any way?

Any thoughts and input is MUCH appreciated!! If you can't tell, I am a Virgo and tend to over think and over analyze everything,lol.