How to increase ulimit in Linux

I've got this ulimit error while installing Oracle EM 12c cloud control.
It said that they expect value of 4096 and my value is only 1024.

Here is what I did to rectify this issue:
1. login as root

2. change sysctl.conf file
vi /etc/sysctl.conf

add on the last row this syntax:
fs.file-max = 5120

save

3. change limits.conf
vi /etc/security/limits.conf

add in this sytax:
*          soft     nproc          5119
*          hard     nproc          5119
*          soft     nofile         5119
*          hard     nofile         5119

save

4. reboot your system

and now when you run this command:
ulimit -a
you will see that "open file" is reflected as 5119.

Hope it helps to solve your issue as well.

another link that is helpful as well is
http://stackoverflow.com/questions/34588/how-do-i-change-the-number-of-open-files-limit-in-linux