You got further than I did on my first attempt! My parts guy, who is normally excellent, told me that I did not need a special tool, which turned out to be wrong!
I happened to do this on Sunday, when he was closed, so I turned to one of the chain stores for help. They told me I needed one of several different sized tools that all looked the same except for the color (blue vs. red) and dimensions (1/4” vs. 5/16th?). However, they said I could buy both and return the one I didn’t need.
Also, as High Order1 points out, make sure you've depressurized your system. From what I remember, I opened the gas cap for a couple of minutes.
This was for a 98 Mountaineer 5.0L.
I hope this helps.