replacing stock speakers in '99 Alero door panel

I picked up the correct size speakers for my 99 Alero. I planned on replacing the tweeters and door-panel speakers together. First, I sized up the situation. It appeared as though the tweeter is replacible by removing the upper portion of the door panel. However, I need some guidance on the rest of the speaker replacement for the lower-door.

By instinct, I inspected the smallest area to remove and went outward. It appears as though the speaker 'grill' is fused, not to mention that the speaker would be too large to slip through for installation.

I went to the second larger kick-panel portion which also seems fused.

The only step that I can think of is removing the entire door panel to replace the speakers. I wanted to check-in to see if anyone had any advice before I jump into the replacement. Obviously, I don't want to make extra efforts that could be risky or avoided.

Plus, the only speakers I've replaced in the past have been ones where the grill was the only item removed.

So, any advice, instructions or wisdom anyone has to share is appreciated greatly!!!

Welcome to AF !

I have a thread that might help you out with this.
Covers most N-bodies, if you need anything else just ask.

Disassembly of your 99+ N-Body Interior (http://www.automotiveforums.com/vbulletin/showthread.php?t=625171)

Also the speakers are a 4x6 or something.
You can make a round 5-61/2" work Like I did.

Hope that helps!