you will get a popup for username and password. Give admin, admin as credentials.
Step3 :
You can see composer in the list of applications. Click on undeploy button parellel to composer.
After undeployment, stop tomcat service and delete composer folder located in ~Tomcat55\webapps folder.
Step 4 : start tomcat service again.
again log in to tomcat manager page.
Now you will not see composer in the list of applications.
Now go to war file to deploy option ( in the same window) . Browse for composer.war file and click on deploy. (you can see message OK if your war file gets deploys correctly)
Step 5 : restart the tomcat . again go to tomcat manager page and ensure that composer is there in list of applications and it is started. click on composer in the list of applications.