Sniker--whatever you do, don't grind your rim---but DO please watch this excellent video that shows clearly the technique to work with hard rim/tire combinations
oh, and buy some inexpensive PEDROS tire levers, they are usually yellow and come in a pair, and are super super strong.
The video is wrong. It matters where you start, and beginning at the valve is a handicap..
Rims have a shallow depression in the center.
To get the last bit of bead over, you need the rest of it in that depression.
At the valve hole the depression is occupied by the valve stem so that can't happen.
Start 180 degrees opposite the valve. Finish by continuously moving the bead towards the center, maintaining tension, and milking the slack to the end. Flip it with your thumbs or palms.
You don't need straps if you keep tension on the bead all the way around.
This ignores the gains from using a thinner rim tape. Substituting two wraps of 1 mil Kapton for tradiional rim tapes will get you .0.030" of diameter and 3/32" of additional slack.
Together that's the difference between cussing at tools and comfortably mounting tires by hand.