You will have to compile a more recent version of ICU from source and then recompile the PHP intl extension.
Building ICU from source is pretty standard (configure, make, sudo make install). You can pass --prefix
to configure to select the installation location.
The easiest way to recompile the PHP intl extension is to remove the one you currently have (apt-get remove php5-intl
) and install the PECL version (pecl install intl
). You will be asked for the location of the ICU files.