Spray lubricants can be your friends!

I used a couple very thin flat bladed screw drivers and a small box end wrench to tap like a hammer, I also lightly sprays the joints with WD-40, very very very small taps and small sideways wiggle movements and they will come apart. Maybe have a spare set of hands hold one while you wiggle and tap the one closest to you.
Let the penetrating type lubricant sit over night.
Just don't pull out your BLUE TIPPED wrench and warm thing up there is gonna be gasoline vapors around and lots of plastic or rubber stuff.
Good luck.