>So to confirm: what you’re saying is change the plastic receptor at the end of the wires (connected to the car)
Exactly 100% right.
Just make sure that you only cut the wires in the connector once you have the new spade connectors. Since you're new to this, I recommend only cutting one wire at a time, so you can make absolutely sure that the correct wire goes to the correct spade. Otherwise you could run into polarity problems which basically results in one speaker bumping out (correctly) and one bumping in (incorrectly). This leads to really muddy sound.
This kit for example, is perfect for you as it includes a multipurpose tool you'll use to cut wires, strip wires, as well as to crimp the spades on correctly so they don't go anywhere. On top of that, those connectors don't really have a 'best before' date, so both the tool and spade connectors are handy to have at home if you get more project ideas.