I use a flat head/large flat head, i hit it with a hammer, and then I use the biggest pliers I have to tighten them as much as I could. Then I heat-shrink wrap them.
I use a hammer too, I always make sure there is a little wire sticking out (where the 0 is) so I could solder all those wires. Give it a good pull, if it comes out u did a bad job. lol