Unlock APEX admin user (when apxchpwd.sql doesn't work)

First we need to find the Apex admin accounts user_id. We do that with the following statement.
You might have two. Mine was the second one

select user_id from APEX_040200.WWV_FLOW_FND_USER where user_name = 'ADMIN' order by last_update_date desc;

Set a new password for the Apex Admin with the user_id we selected.

update APEX_040200.WWV_FLOW_FND_USER
set web_password = 'password'
where user_name = 'ADMIN'
and user_id = 56502607595642;
commit;

Then we unlock the Admin account with this statement.

alter session set current_schema = APEX_040200;
begin
wwv_flow_security.g_security_group_id := 10;
wwv_flow_fnd_user_api.UNLOCK_ACCOUNT('ADMIN');
commit;
end;

Install Oracle 11gR2 XE on Centos 6, Oracle Linux 6, RHEL 6

This little HOW-TO shows you how download and install the 64 bit version of Oracle 11gR2 XE APEX
on CentOS 6, Oracle Linux 6 and Red Hat Enterprise Linux 6 (x86_64)

Download Oracle 11gR2 XE from www.oracle.com
Open a terminal and become root, then go to the folder you downloaded the file to.

su - root
unzip oracle-xe-11.2.0-1.0.x86_64.rpm.zip
cd Disk1
rpm -Uvh oracle-xe-11.2.0-1.0.x86_64.rpm
/etc/init.d/oracle-xe configure

Thats it!

You can now stop and start the database with:

/etc/init.d/oracle-xe stop
/etc/init.d/oracle-xe start

You might also want to add the oracle binaries in your $PATH so you can access sqlplus, rman and other commands.
Open a terminal and become root. Then cut n' paste the script below into:
/etc/profile.d/oracle.sh

su - root
vi /etc/profile.d/oracle.sh

Enter this script:

if ! echo ${PATH} | /bin/grep -q /u01/app/oracle/product/11.2.0/xe/bin ; then
PATH=/u01/app/oracle/product/11.2.0/xe/bin:${PATH}
fi

Save it, then close the terminal and open a new one for the change to take effect.
To access the webgui and/or apex:
Go go http://localhost:8080