How to Delete Preinstalled Android Application

When buying an Android phone, sometimes it comes with preinstalled applications either from manufacturer or network operator. These preinstalled applications can not be easily removed from application manager unless you have root access. If you already have root access, follow the following steps to remove the preinstalled applications:

Login into Android shell, you can use adb tool or terminal application such as Android Terminal Emulator .
Type su to login as root
Type mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system to enable read-write mode
Type cd /system/app, to enter the applications directory
Tyle ls to view the list of existing applications
Type rm AppilicationName.apk to delete an application. For example, to delete Facebook app, just type rm Facebook.apk