Now extract the Odin3 zip file on your desktop or desired folder and place the TWRP zip file in there as well, place the RMM-State Bypass Mesa v2, Magisk v18.x and HadesRom Oreo Stock v6.0 on your micro-SD card.

• Power off your phone.
• Hold the following buttons: Home button + Power button + Volume DOWN button, this will load you into a green screen with "downloading".
• Start Odin3.
• untick the Auto-Reboot.
• Under AP select the TWRP zip file you placed in your Odin3 folder.
• Click Start.
• Wait for the Odin3 program to say Pass, a big green box that says Pass right below the Odin3 program header.
• Hold the following buttons: for all the 3 Galaxy A series Power button + Volume DOWN button to power down your device.
• Hold the following buttons: For the A3 Volume Up + Home Button + Power Button, A5 Power button + Volume UP + Home button, for the A7 Volume Up + Volume Down + Power Button, and release on the Samsung, screen to enter TWRP.
• Swipe to unlock or simply select Wipe.
• Tap: "Advanced Wipe" and select: Dalvik Cache, Cache, Data, System.
• Select wipe again and tap the: Format Data(this step is only needed when coming from the stock ROM"
• Tap the "Select Storage" button and select your micro-SD card.
• Select the RMM-State_Bypass_Mesa_v2.zip.
• Now swipe the "Swipe to Confirm Flash"
• Select and tap Reboot and select "Recovery".