(Note: Michael posted this to the Yahoo! 206 club in May '01 and is reproduced with his permission, thanks Michael!)
(Usual Disclaimer, do this entirely at your own risk!)
OK guys, rear speaker change is a bit more awkward!! Because it is such a big job, I strongly recommend you use to opportunity to give the rear some well needed sound-proofing as well!!
Same equipment will be needed as for front speakers, but in addition you will need a spanner/socket to undo a bolt - the bolt is spark-plug size.
First you need to remove the lower rear seats - pull them up and then squeeze the big metal clip together (you'll wish you'd spent more time on the pec-deck at the gym while trying this, it's a fairly stiff clip!) so you can remove the lower part of the seat - put it out the car somewhere.
Then you'll see where the seatbelt is attatched at the bottom - pull the rubber cap off and undo the bolt. Careful as you pull it out, store the cap, bolt and spacer somewhere safely.
Now move to the boot. Open the boot, there is a white panel covering the boot sidewall (higher up), where the rear seatbelt pops out of. This needs to be removed as it covers part of the main side panel which we want to remove. It is secured with two star-screws - locate these (both on bottom edge of panel, one near the back the other hidden behind the carpet towards the seat) and undo.
Move the rear seat forward a bit, and then pull the panel away and hang it in the boot (it still has the belt running through it so you can't move it out).
Now move back into the rear of the car. Open the rear windows and pull the rubber trim up away from the panel. Now do the same with the rubber door trim on the edge of the panel - pull it all well away. Now using the belt slot as a hold, carefully pull at the panel - it is secured with pop nuts also, you should here them release. Do the same at the back of the panel, which is now exposed with the white boot panel reomved. Now the difficult bit!!
With the panel unsecured, you now need to remove it and hang it outside the car (as it will still have the belt running through it so it can't be completely removed). There are two problems with this - the clip attatching the b-pillar cover (where the passenger seatbelt hangs) to that panel and also the bottom of the panel which is tucked behind the passenger seatbelt retaining bar.
First prise the b-pillar cover away a bit and unclip from the main panel.
Now pull the panel UP and FORDWARD, it will take time and a fair bit of strength! The difficult bit is pulling the panel past the b-pillar. you have to pull up at the same time to move the bottom of the panel past the passenger seatbelt retaining bar. Not much detailed info i can give you on this - it is quite literally pull it away. Don't be afraid to really pull it - you will need to, and the plastic is very strong and flexible.
When you have done this, you will be able to see the speaker surrounded by foam and screwed into the car panel. Remove the foam and enscrew the speaker. Remove it and cut the wire clip, and as with the front speakers, use wire connectors to connect the wire for the new speaker.
Now pull out the padding from the space in the panel, and stick your sound-proofing material to the car's panel. Replace the padding (all the sound-proofing is useful).
Now screw in the new speaker and re-stick the foam around it.
Now slide everything back in, reverse of above procedure!!
It sounds complicated, but to do both rear sides took me only a afternoon - basically hope you're other half doesn't mind loosing this bank holiday monday!!
Need anymore help, give me a shout,