I would recommend disconnecting your battery first for this one. Just in case. Also be careful when handling the door panel (airbag)
First step is to remove the door handle trim to access the screws underneath. Proceed to remove all screws from the door. Dont forget the one underneath the Airbag label.
http://www.318ti.org/forum/attachmen...1&d=1400299485 Next, you will have to carefully pry the whole door panel off, starting from the bottom. I managed to pull the clips off the glue on both my doors accidentally, so im not sure how its "supposed" to be done. So once the bottom is loose, you will need to push the panel over the lock on the rhs, and then pull the whole panel outwards. Along the top of the door, it is lined with small metal clips. These wont break, just pull. Remember to disconnect the door handle and power mirrors before removing. Once you have the panel off, you can check the plastic clips from the bottom half. If you see glue (i.e. if the clips are still hanging on to the door) then you may have to just glue them back on (correct me if im wrong, but those clips really confused me). I didnt, and the door panel isnt very secure any more.
In the picture, you can see the clips still hanging on to the door
http://www.318ti.org/forum/attachmen...1&d=1400299485 Now remove the speaker housing with a screw driver. Once you have that free, you'll have to do some serious demolition work. First of all, pull the foam ring from the housing (
http://www.318ti.org/forum/attachmen...1&d=1400299485) This comes off very easily.
Next, use a utility knife to cut the rubber around top of the speaker to remove the cone. After this, I used a grinder to melt the plastic arms connecting the magnet. Try getting the cuts as flush to the edge of the housing as possible. If you can think of a better way to get these off, go for it, but I thought a grinder was a pretty good idea. (Dont cut the wires from the adaptor)
http://www.318ti.org/forum/attachmen...1&d=1400299485 You should be left with this (
http://www.318ti.org/forum/attachmen...1&d=1400299485)
What you should do now, is take a hack saw and cut two straight lines down either side of that clip, because if it stays, you wont fit your speaker in. Make a cut at the bottom of the clip too, and just bend it and snap it free.
Slot your new speaker into the housing, and either drill holes to screw the speaker in, or just leave it. Mine was snug enough that I didnt bother. Solder the new speaker to the adaptor you cut off so it is hanging through the hole you cut it out of, (its a good idea to have extra wire length) and put the foam ring back on. Now screw the housing back on the door. Connect the plug to the loose adaptor, and have fun trying to wrestle the door panel back on.
This guy
http://www.318ti.org/forum/showthread.php?t=17528 has a lot more pictures, except I think he put the speaker backwards in the housing, im not sure (the pictures confuse me) But you should be able to put your speaker in the same way the old one was.
Its your choice whether or not to glue the clips from the door back on (if they came off) But honestly I have no idea how you would get it back on, because they all face different directions. I didnt, and it just rattles a bit if you slam the door (which you shouldnt anyway...). So maybe someone else can explain this.
I havent posted pictures before, so I have no idea if you will be able to see them linked. Sorry if its wrong.
Anyway, thats all, just remember to connect the power windows and door handles back on, and reconnect your battery too. If you have any questions, shoot. Any fixes? Tell me. Any better methods? Tell me as well. Thanks
Does anyone want to know the process for replacing stock speakers in an e46ti? 
Linear Mode
