How to change Weblogic Default password?

Please follow the below steps to change the Weblogic login id or password from previous value to something else:

1).Move inside your Domain Directory.

Example: (here WLST_Domain is my Domain Name)
C:\bea\user_projects\domains\WLST_Domain

2). move inside the Servers directory
Example:
C:\bea\user_projects\domains\WLST_Domain\servers

3). Move inside the Admin Server Directory...In my case the Administration Server name is "AdminServer"
Example:
C:\bea\user_projects\domains\WLST_Domain\servers\AdminServer

4). Take a Backup of "data" folder, Means Just rename "data" directory to some other Directory like "data_OLD"

5). Inside AdminServer Create a directory with name "security"
C:\bea\user_projects\domains\WLST_Domain\servers\AdminServer\security

6). Inside the "security" directory Just create a file with the name "boot.properties"

7). Inside the boot.properties file Just enter the UserName and Password in two lines

Example: below is the content of "boot.properties"...only following two lines

username=weblogic
password=weblogic

8) Start the WebLogic Server

Note: If you are using WebLogic 10.3.1 then the default password may be either "weblogic1" or "welcome1"