Info gathered from IRC discussion with tsurdilo:

1) install git

2) git clone https://github.com/bpmc/bpm-console.git

3) mvn clean install -U  -Dfull -DskipTests

4) mvn eclipse:eclipse

5) git clone https://github.com/droolsjbpm/jbpm.git

6) mvn clean install -U -Dfull -DskipTests

7) git clone https://github.com/droolsjbpm/jbpm-form-builder

8) mvn clean install -U -Dfull -DskipTests

9) open eclipse, import projects.

10) search pom files in jbpm for "<version>2.3.5.Final</version>" and replace with "<version>2.4.0-SNAPSHOT</version>". This tells to use local version

11) change bpm-console code -> compile console code -> compile jbpm code

12)after that go to your $jbpm/jbpm-distribution/target dir

there you will find the distro zips you just built

next steps:

13) copy jbpm-5.4.0-SNAPSHOT-bin.zip and jbpm-5.4.0-SNAPSHOT-gwt-console.zip from $jbpm/jbpm-distribution/target dir

to $installer-dir$/lib directory

15) in $installer-dir$ run:

ant clean.demo

ant install.demo (or ant install.demo.noeclipse if you dont want eclipse)

ant start.demo (or ant start.demo.noeclipse if you dont want eclipse)

Keep in mind that stepps may varry between versions. so I this doesnt work than join irc channel #jbpm on freenode and ask for update. And ofc If You find that this article should be updated than write a comment with update so I can edit the article.