Here is a crude idea of some of what I did.
The tool is what I use to take terminals out of the pesky Suzuki connectors.  The drill bits need to be less than an 1/8 inch.
Use the smooth end, and make sure it fits in the small groove of the terminal retainer.
A small screw driver with the wide sides ground off works great on regular spade terminals.
Keep the metal cool as you grind these. I use a little bit of oil to keep dipping them in.
If it turns blue, redo.