I would think doing something like that would be a very daunting task. Much easier to to install vl7.0 to a separate partition using the same user name and password, then transferring everything over from the visible home directory.
Then from the hidden directories transfer over...
.gftp, .ssh, .mozilla, .config/Thunar/uca.xml and any other config file for programs you use regularly.
note...(.config/Thunar/uca.xml will give you thunar custom actions again, but all the icons will not be present.)
note2 (anything you transfer from .config directory will not transfer if you did not set up with the exact same username.)
If you do not have a partition already and do not have the space to create one, you can do the following...
Format an external harddrive the same as your vl60 install. Example ext3/ext4 which ever with gparted.
Transfer as above everything you want to save.
Install vl70 (using same username, password (password being the same probably is not necessary.)
Then transfer the data you wish to keep to your fresh install of vl7.0.
I've done the first option about 15 times as I've reinstalled just about for every alpha and beta release of vl7.0. Have not lost any data yet.