I'm a bit late to the show here, but I recently replaced my door speakers as well, and I know your struggle. Unfortunately I did not take any pictures, but here's the best way that I found to get them in there:
1. When you remove the old speakers, there's a black spacer that's bolted onto the door with three bolts. Remove this.
- There is a plastic alignment pin sticking out. Cut this off so it's flush.
2. Loosely screw in the first screw to attach the new speaker to the spacer bracket thing you just removed.
3. The remaining screw holes didn't match up for me exactly, so I had to angle the screws through the speaker frame holes to get just the tip of the screw into the spacer hole.
4. Once you have the tip of the screw in there, start screwing it in while applying a little pressure to get the screw to angle back up. I didn't need much pressure; the screw just kind of righted itself up on its own. Don't tighten this all the way down yet.
5. Rinse & repeat for the last hole. (You might only need to do this for the LAST hole anyway)
6. Once you got 'em all in there, finish tightening up all the screws. Make sure not to over-tighten them!
The plastic spacer should flex enough to allow you to make this work. It did for me anyway. Then once you have it all screwed in, just bolt the spacer back onto the door and you're good to go!
This may be a little too late for you, but hopefully it'll help someone else in the future!
