Once that has been done, just put the DVD into the optical drive and when it mounts hit the installer.
it will NOT wipe out anything on your drive, but just in case, that's what the TM backup is for.
If you do not take a TM backup, your install will almost certainly, fail.
I had a few problems as you might have read from previous posts, but I have successfully installed Mavericks on my early 2011 Macbook Pro. I need to install El Capitan for compatibility with the programs I need. I am scared to death that I'm going to mess up the Mac. El Capitan is no longer available through app store So I bought a bootable CD on ebay. I'm not sure what I need to do to install it. I would just like to do an upgrade rather then wipe out everything and start from scratch. I have upgraded the ram on my pro to 8GB and had to remove that and install the original 4 GB in order to get Mavericks to install because of panics. Then put it back in after install. Any advice would be appreciated. Thanks