I would recommend starting over at the beginning.
I would make a dummy round, starting with setting my sizing die. Then I would set my expanding die, then my seating die, and then my crimp die. After making one (only one) dummy round, I would check it to make sure it plunks.
If it passes the plunk test in your barrel, make another dummy or two to make sure the process is repeatable. If it is, you're good to go.
I have no problems making, fabricating, or modifying things, BUT (and it's a big but) I would try the above before grinding on the die. IF you do that, and it doesn't work, Lee may not warranty it for replacement, even though they (whoever the CS rep was) told you to do that. They should have told you to send it back so that they could do the modification.
Just my .02c.
chris