bought some 4" speakers off amazon, https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
got the nerve to pop off the 26 year old door paneling to get to the speakers and I was pleasantly surprised that they came off with out tearing thru the cardboard backing or plastic pop rivets breaking, of which as a reference both my '96 Corrola and '99 4Runner did.
only 3 screws, one where door latch is, one where door handle is and one near the dash, it is covered by a plastic cap.

IMG-1196.jpg
IMG-1198.jpg
IMG-1199.jpg

It did have some, what I believe to be white lithium grease on the clear plastic barrier, not sure why or how it got sprayed there but it wiped off easy.
Now for the stock speakers,
IMG-1200.jpg

the 2 screws came out easy but the speaker did not want to budge. hit a few times popped right out, no damage to bracket.

The new speaker holes did not line up good enough with the stock bracket so drilled some new small holes and had some bolts,nuts and lock washers from a bolt kit bought from Harbor Freight.
I spliced the lines, put the blue to positive. hoped it was correct because the old stock speaker didnt show which side was what.

IMG-1202.jpg

seems to work fine.
IMG-1205.jpg

Just need a better radio, the current one is trash and wont turn on every time, may be a short but one thing is for sure, it was a very cheap radio and I can hear parts rattling around in it. so planning on buying a new one with brackets because its currently sliding around in the double height spot in the dash.

For those who want to chance putting a larger than stock up front.
IMG-1204.jpg

Not sure about clearance more than its not a perfect 5" diameter circle and I didn't check the depth.
anything is possible with a harbor freight near.