No trimming needed. They sound much better Than stock the rear passenger speaker was blown.
The dash speakers fit nicely and were very easy. I screwed the driver's side speaker into the existing holes. On the passenger side I removed the factory amp and mounted it behind the dahs opening using the included little clips instead of mounting it to the panel.
The door speakers were a little more trouble. I put some foam down to space the front ones out and had to drill a few new mounting holes.
The rear speakers needed a spacer and some new holes drilled.
Do your dash speakers put out any meaningful sound?
I still have the OEMs but the sound out of them is insignificant. They are not blown, just not amplified enough.