HA! You have to solder. I have connectors like that for the speakers on my guitar amplifier. If you can find the right connectors, it should slip right on. I prefer soldering for a more secure connection.
Make sure you calculate the right resistance when you wire your subs. If you wire them parallel (most common) resistance = 1 /sum of resistance on subs. If you wire in series (straight line) its just resistance + resistance. If you don't match resistance right to your amp, you're getting less power and could
possibly damage your system. But you already knew that. Good luck and post when you get it working.