i always snakebite my tubes when i use levers. its always kind of risky to jam anything in there to install a new tube/tire.
if youre having trouble getting those last couple inches onto the rim, make sure the bead you already have on is seated in the very middle of the rim, where the diameter is the smallest on the wheel. that usually does the trick for me whenever a tire is giving me difficulty. then roll it till youve got blisters.
EDIT: oops. sorry for the repitition of advice. my bad.