Rep Power: 0

I recently got a used '96 Civic, and while it's still in pretty good condition (only had about 80k miles on it) the one thing that was really broken was the sound system. Although they had upgraded the thing (has a JVC audio system in it, with some random brand's speakers) the only speaker that really works is the front passenger side one, the rest kinda' suck/don't work at all.

I've decided to buy a Pioneer - 50W x 4 MOSFET CD In-Dash Deck (DEH-1100MP), with Pioneer - 6-1/2" 2-Way Car Speakers with Polypropylene Cones (Pair) for front speakers and Pioneer - 5-1/4" 2-Way Car Speakers with Polypropylene Cones (Pair) for the back speakers.

Now I pulled out the Deck in my car and it already has the din connection crimped as so did the front speakers. The problem I'm facing is the back speakers. I have 3 questions for this:

1) How do you take these covers off? It seems that they are put in backwards so that the tabs that hold it in place are facing you towards the front of the car and not the back of the car.

2) It's to my understanding that the back speakers are 6x9 speakers (don't really know what this means), but my speakers for the back are only 5-1/4" speakers. I know I need a holder/adapter of some sort to use these for my speakers, I just don't know what/where I would get it. Any help with this?

3) I found out for at least the front speakers I needed a Honda speaker adapter, so I bough 2 pairs of Scosche SHHA02B 1990 and Up Honda Universal Speaker Harness. Now I'm not sure (since because of post 1) but is it safe to assume that the connection for the front speakers is the same as the back ones (so buying a second pair of harnesses was a good idea)?

Thanks for the help guys.