restoring Macbook Pro

Sorry to seem to ask the same question ten times, but I need to ask again. I need to give some background so I don't end up with the same issue.



My macbook late 2011 was almost full - 485 GB of 500 used. It also had an issue with the sound which wouldn't repair. Someone suggested reinstalling the operating system. It came with Lion, but I had upgraded to Mountain Lion several months ago. I can't remember how I got Mountain Lion - it seems I probably purchased it, received a code, then downloaded it. I can't find any of that in my emails or anything. So, I first did a time machine backup of all 485 GB. I then tried to reinstall the operating system and after some glitches, received an error message that my HD was damaged and could not be repaired. So then I purchased a new HD and just installed it today. I did command R to get the operating system and Lion was the default OS X.



Now, I'm not sure how to get what I need via the time machine backup. If I do the entire thing, Mountain Lion might install which I do not want in case it is corrupt - it was suggested previously that that could be the problem with the sound. (btw the sound is now repaired with the new HD and Lion installed) I don't need every single thing from the back up - but I do need my Office programs, all of my documents, iTunes etc. I just tried to retrieve those from the back up and don't really know how to do it. Could you tell me the best way to retrieve the files I need step by step. Like how to I initiate the process and then what?



After that, I need to know some possible ways to find Mountain Lion. When I go to App Store and Purchases, it said no purchases. There's no point purchasing it again if it should be accessible somewhere.



Again, sorry to request this information again. I'm a bit stressed out from various things.