I jus took mine apart today to put my door speaker. Took me forever to get that window crank off. I was tugging and pulling and then finally saw that little metal clip that holds it in. Got a screwdriver pushed it out. Door panel fell right off lol. Switched the speaker and made the stupid mistake of not trying it out before putting everything back on. I think I crossed the wires cause it is super low. And yes it is a 2 ohm speaker so it's not that 4 ohm problem. But yeah one thing to remember when putting back on the door panel is start from the top and then snap it to the bottom. I kept snapping the bottom in place first then struggled getting the top to seal right. Finally I slid it first from on top then snapped in the bottom perfect. Good luck bro. If it is your first time, just take your time and try things first. Have fun!
Edit: The positive will be the red wire, the negative is red w/black. Keep track of which one is which because I was looking at my old speaker I took out and saw that the top part was red first then red w/black next to it. The bottom was reversed. I think that is where my mistake is.