As for git client, personally I use TortoiseSVN, but I have to hit it with a hammer to make it work, so I guess I can't help you there.
How do you do to use TortoiseSVN on GitHub?
1. On the GitHub page, click "Clone or Download"
This should open a smaller box that starts with "Clone with HTTPS"
2. Copy the URL from this box. (Downloading the zip is, for the most part, easier, but doesn't make a local repository, and thus doesn't use TortoiseSVN.)
3. Select the folder on your computer you wish to store the repository. It must not be write protected, and should be empty.
Assuming TortoiseSVN is installed, when you right click the folder, you should have the option "SVN Checkout..."
4. Selecting "SVN Checkout" should cause another window to appear.
I don't know what any of the options mean, but the URL at the top should be the URL you copied in step 2 (paste manually if not generated automatically). And the Checkout Directory should be the directory on your computer you wish to keep it.
If checkout depth is "Fully Recursive", and revision is "Head Revision", you can click OK and it will start the download.
It should create three folders: Tags, Branch, and Trunk. (and a hidden .svn)
The download will take a while, because each of these folders has one or more copies of the LCS source code (and especially the music files), since I only barely know how to do this.
"tags/v4.10.0" should contain the version you're interested in. I think.
The trunk folder will contain the very latest version, but I'm not sure it's working.