“You remember how you used to always play that song on your dad's stereo?”

You run into a close childhood friend that you haven't seen in several years. You're talking to each other about the past. You remember something that happened to you a few times when you were both kids. You say:

You remember how you used to always play that song on your dad's stereo?

you remember (something)?

When you're asking a question to a friend or family member, you sometimes leave "do" out of the question. A more formal way to ask this question is:

Do you remember how you always used to play that song on your dad's stereo?

remember how (clause)

When you are remembering a past situation, you can say "remember that (something happened):

Do you remember that we dressed as super heroes for Halloween in fifth grade?

However, this only means to remember the fact that something happened. A good answer to this question would be just "yes" or "no". When you want to talk about remembering the experience of an event, you use "remember how (something happened)":

Do you remember how we dressed as super heroes for Halloween in fifth grade?

The proper response to this question is to describe some detail of that memory:

Yeah, I was Batman and you were Spider-man.

(someone) used to (do something)

You use the phrase "used to ___" when you're talking about memories of the past. It's used to describe something that you did several times — not just once or twice.