I was doing maintenance and saw the floating yellow foam "stick" in the reservoir was brown at the bottom 3". I wondered what it could be that made it brown. I pulled it out, wiped of a brown muddy slime.

I get the feeling the reservoir is contaminated. I want to remove the neck and res tank but I can't seem to find a way. I've looked at an exploded view to figure out a way to get at the reservoir and still can't figure it out.

I want to remove it, hopefully clean it, or replace entirely. Search for how to online, no luck.

Does anyone know a way?