Modify Android 7 Firmware: Replace Home Screen

I need an experienced Android developer to modify the Android 7 firmware on my device. The goal is to replace the home screen with a pre-installed app.

Key Tasks:
- Modify Android 7 firmware to replace the home screen with a pre-installed app.
- Ensure seamless functionality of the app as the home screen.
- Remove all existing home screen features, including the notification bar and quick access to settings.

Ideal Skills:
- Extensive experience with Android firmware modification.
- Proficiency in working with system-level permissions.
- Ability to troubleshoot and resolve firmware-related issues.

Please note that I am unsure if the pre-installed app is already system-level or if it will need system-level permissions. Therefore, a deep understanding of Android's system-level architecture will be advantageous.