uninstall libxml2 from postgres 9.4

Hi all,
I'm looking for  how to uninstall libxml2-2.7  from my system redhat6.5.

I both installed  from source packages   libxml2-2.7 and after
libxml2-2.6.28  and rebuilt it with postgreSQL 9.4 .
Because my application need to  use only libxml2-2.6.28. version.I must uninstall
libxml2-2.7 version one.
When   query    like    'xmllint --version' , I  always get answer:

   xmllint: using libxml version 20702.
So I need to remove  libxml2-2.7    How can I do it ?
  Thanks  all for help

  koff