The most recent binary build of Wonder frameworks for both WO 5.3.3 and WO 5.4.3 are available from mDimension's Hudson build server. This installation method gets you the latest version.
However, if you are not afraid of source (and you shouldn't be!), then try the Source installation and upgrade article instead. Really, working with Wonder source is the recommended way, and you will learn more and be a better WebObjects developer as a result :-)
The objective is to simply download the compressed archive of the Wonder frameeworks, expand the archive and copy the frameworks to the default frameworks location.
Open a terminal session and type the following easy commands. Choose the one for your WebObjects version.
If you have a custom environment layout
If you want to install the frameworks somewhere other than the default location, replace "/Library/Frameworks" on the last line above with the desired destination