What is the best way to create individual subject correlation matrices from the HCP rfMRI data?

Hello all,
I would like to know if anyone has any advice for or experience with computing correlation matrices from the HCP resting state fMRI data. There seems to be two main avenues:
(1) download a file(s) for each subject that I would like to study and extract the time series for each ROI given a parcellation.
(2) download a group average eigenmaps file from connectome db from which each subject’s scan data is reconstructed then proceed as in (1).
For the first approach, which data should I actually download for each subject? There are quite a few files available, and I would like to avoid as much preprocessing as possible. And of the files that look like candidates, there seems to be two for each subject (one LR and one RL) - do these need to be concatenated in some way?
For the second, I have been unable to find any explanation on how to actually generate individual subject data from the eigenmaps and group average data. Does anyone know where I could find the documentation or code for doing this?
Any advice or input from someone who has generated correlation matrices from this dataset is greatly appreciated - Thank you!

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