I know, too late, but next time it will be way easier to just buy a new boot...
I used every cuss word in the book, tried the roll method, tried lubing it up, walked away and tried the next day, and I finally ended up ripping the boot and ruined it

I think it was Smokin' Joe that offered the advice to just get a new boot. Lemme tell ya, it was soooo easy

Ya see, the old boots are all at least 13 years old now (mine is a '97, and was 15 years old at the time). The old rubber is/was stiff and impossible to get in to position, where the new boot is/was soft and pliable, and went on without any fuss at all.
Live n learn

Black Dog