You see that bubble next to "Reply w/Quote" with the "..." inside it? Click it and it'll turn red. This applies to every post in any thread. Once you're done clicking the Multiquote button, click "Post Reply to Thread" near the top of the page and the posts you've chose to multi-quote will show up.
I'm so proud of you.
(I'm 17)
They don't know about us 
I love a daring man.