I think you're mistake about this one: this is a plastic lock.  The
Chevy book says you just squeeze it with your hand, which I'm sure would
work on the factory floor.  These had gotten a little brittle.  Anyway,
even the Chevy book doesn't call for a special tool - just your hand.
And, BTW, for the 'metal' disconnects, I did get the tool.

So, thanks for not very much.

George

Why would anyone need to "buy" fingers?  That's the only
"special" tool you need for this setup.  Unfortunately, the
op has run into a common situation where the area where
the quick disconnect is has probably become crammed with
dirt....maybe some corrosion.  In these cases, I usually liberally
spray some type of lubricant in there while pulling back and
forth on the line and turning the line.  Eventually, you can release
the plastic tabs.

But since you don't have the tabs anymore.....it could be a little
bit more involved.

Ian