How do i properly bridge a 4 channel amp to a 2 channel?

Hey, I think I kind of have it figured out but I just want to make sure Im doing it the correct way. First off the amp is a JL e4300. Its 45x4 or 90x2. Now Im doing this so I can run more power to my front components and just use the headunit's power for the rear fill. Do I connect the first speaker to the positive on the first channel and the negative on the second channel? And so on for 3 and 4? If that is correct then how do I go about it when I adjust the gains? Do I just keep them at the same voltage? I never bridged an amp before so any help would be great. Thanks

Ok so I did a little more reading. Now from what I read it sounds like I am only running one pair of rca's to my hu connected to front. My rear wont be connected on the hu. Then I have to run two y cables from the other ends to the amp? Does that sound right? Also, im still confused on how to go about setting the gain controls when im bridging the channels.

I am looking right at the manual and it is just confusing me a little bit. I would prefer someone that has done this before to give me some insight.

Ok so I set the gains to the same voltage for all the channels then. This will be stereo bridged correct? not mono?

Mrchyzy, Neuman here is our resident audio guru. I would take everything he says at a pretty high regard (unless he doesn't like you). He's helped me out of a jam or two. And yes, set both gains matching. As far as the stereo/mono, i dunno.

Yea I kinda figured on the gains. I have bridged a amp before but that was for a sub. I have never done a 4 channel amp to be used by 2 speakers. I thought I read somewhere that the reason for the splitting of the rca's into a y adapter was to get a stereo output. I just wanted to make sure that I was doing it correctly. Thanks