Using the multi-Quote is pretty easy but thought It will be better to write it down for those who find it difficult.
Step 1 is to find the thread you want and select the posts you want to reply to as shown on the photos:
Step 2 is to click the small pop in window on the right hand side of the screen once you're finished selection
Step 3 is to write down your answer to the quote and submit the reply
Easy! :) Thank you all.