1970 Dodge Dart grommet installation

[PikaPhantom]

I'm trying to install a grommet in a 1970 Dodge Dart. Right now I have the grommet where it's suppose to be in the gas tank with the thicker side sticking out. Im having problems sticking in the tube where gas travels to the tank into the already installed grommet. I've tried silicone greases but that doesn't seem to be working. I don't know if I'm just not able to use enough brute force or something but if there's anything else I should try please enlighten me.
Thanks

 

[Johnny Dart]

Wd40 on the outside of the filler tube, and around the inside of the grommet. Wiggle/Spin/push the tube in.

 

[Tooljunkie]

Heat gun used sparingly will help too. Or pour boling water over it.
Heat will help it become pliable

 

[harrisonm]

Combination of the two. Soak the grommet in very hot water, then use the WD40. It will work.