svn:externals command for changing a property

I am pulling some of my code into a folder through svn externals. I know how to see the svn externals using "svn pget" command but not sure how to change the tag dependency from 2.0.0-b-21 to 2.0.0-b-22. How can I do it through SVN command? I know how to do it through Windows TortoiseSVN but not through Unix.

secdevapp03.gspt.net $ svn pget svn:externals http://devsvn.gspt.net/svn/components/store-analytics/开发者_高级运维myapp-analytics-rules/tags/2.0.0-b-21/src/main/resources/analyticsPlatform/myapp src/main/webapp/WEB-INF/analytics-platform-rules/myapp

Please guide.

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The documentation says :

In addition to the propset command, the svn program supplies the propedit command. This command uses the configured editor program (see the section called “Config”) to add or modify properties. When you run the command, svn invokes your editor program on a temporary file that contains the current value of the property (or which is empty, if you are adding a new property). Then, you just modify that value in your editor program until it represents the new value you wish to store for the property, save the temporary file, and then exit the editor program. If Subversion detects that you've actually changed the existing value of the property, it will accept that as the new property value. If you exit your editor without making any changes, no property modification will occur:

svn propedit svn:externals src/main/webapp/WEB-INF/analytics-platform-rules/myapp