Step 4 of this procedure is vague

[John Goetz]

This question is in reference to Atlassian Documentation: How to Use System JRE Instead of Embedded JRE

Step 4 of the procedure says: 

Change the JRE_HOME value with the absolute path of your system JRE.

Is this referring to the environment variable or something else? It isn't clear from the procedure.

[Volodymyr Krupach]

It's referring to editing of catalina.sh or catalina.bat.

Step 4 is continuation of step 2, 3 and you are still editing catalina.sh or catalina.bat. Step 5 says to save the changes.