upgrade php4 to php5

[madunix]

how can i upgrade my php4 to php5?

[root at intra /]# uname -a
Linux intra 2.6.9-5.ELsmp #1 SMP Wed Jan 5 19:30:39 EST 2005 i686 i686
i386 GNU/Linux
/usr/local/apache/bin/apachectl stop
cd /downloads/
cd php-4.4.3
./configure --with-apxs2=/usr/local/apache/bin/apxs
--with-mysql=/usr/local/mysql --with-zlib-dir=/usr/lib/
--enable-versioning --enable-track-vars=yes
--enable-url-includes--enable-sysvshm=yes --enable-sysvsem=yes
--with-gettext --enable-mbstring --enable-ftp --enable-calendar
--with-config-file-path=/etc --with-oci8=$ORACLE_HOME  --enable-soap
--with-gd  --enable-xml --with-xml  --enable-sysvsem --enable-sysvshm
--enable-sysvmsg --with-regex=system --with-png --with-ttf=/usr/lib
--with-freetype=/usr/lib --enable-sigchild --with-openssl --with-iconv
--with-dom
make
make install
/usr/local/apache/bin/apachectl start


what would be the best way to upgrade to php5?
any modification should be done on php.ini?

your input would be really appreciated?

Thanks
-mu