1. How to flash roms ?

  1. Get rom For your device from xda or some where else .
  2. Get the twrp for your deivce ( It can be found on that thread where you downloaded rom. ).
  3. Flash the twrp you can watch this tutorial if you don't know how to flash
  4. Reboot into recovery mode by using rebooter app.
  5. Go to install option in twrp .
  6. locate and click on that rom which you downloaded from thread .
  7. Swipe to flash and reboot system
  8. Now you should see different bootanimation.(That means you did that without any issues)

2. What's difference between Odex and deodex or Which one Should i Download ?

Odex

  1. It's made For faster boot
  2. It's decreases ram usage
  3. It takes more space in /system partation
  4. Device runs smooth

Deodex

  1. It uses more ram as compared to odex
  2. More free space in /system partation so you can add more inbuild apps or features
  3. Takes lots of time to boot up as compred to odex
  4. Device lags and uses more battery

What is xposed build ?

  1. The Xposed Framework is a way to make system-level changes to your Android operating system without installing a custom ROM. All you need is root access. Here's a look at what you can actually do with the Xposed Framework. You'll find all of these modules listed in the Xposed Framework itself.
  2. It can be found here xposed installer