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:
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Step 2 is to click the small pop in window on the right hand side of the screen once you're finished selection
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Step 3 is to write down your answer to the quote and submit the reply
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Easy! :) Thank you all.