Learn how easy it is to sync an existing GitHub or Google Code repo to a SourceForge project! See Demo
Follow the instructions in this Help post:
to either replace the existing version 4.2.4 installation or to upgrade to version 4.3.0. You should upgrade to version 4.3.0.
In either case, there's no need to make a backup of the database or of the GEDCOM first, and there's no need to re-import the GEDCOM after the installation. The database is the same for either version. All you're doing is replacing the program code while retaining the data and configuration files.
To download the most recent SVN version, which hasn't been updated in several months, don't use the download location in the above Help topic. SourceForge changed the SVN repository structure. Instead, click on SVN at the top of this page, then click on trunk, then click on phpGedView, then click on Download Snapshot. The system will respond with a message about checking the snapshot status and either begin the download immediately or tell you that it can't find the snapshot. If it's the latter, wait about 15 minutes and try again. This happens when nobody else has tried a snapshot download recently.
If you follow the above download instructions, you'll end up with a ZIP file that contains a lot of junk as well as the desired "SVN" version of PhpGedView. What you want will be in the directory "phpGedView". Everything else is garbage. I don't have enough authority to get SourceForge support staff to clean up the PhpGedView SVN repository.