diff -r 1de74ac0628f -r 31b3d00edb8a src/source/developer_guide/howto-rename.rst
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/source/developer_guide/howto-rename.rst	Tue Dec 11 16:29:56 2018 +0100
@@ -0,0 +1,67 @@
+.. _renamehowto:
+
+
+How to rename classes of existing objects ?
+===========================================
+
+
+PyAMS provides `zodbupdate` script to update easily update the change in ZODB. Because, when you develop new features
+to PyAMS we sometimes have to rename or modify classes of already stored objects and if you do that you will never access
+yours objects
+
+
+**1) Include you package in the require resource for you webapp**
+
+
+.. code-block:: python
+
+    requires = [
+        'mypackage',
+        ...
+    ]
+
+**2) Add the Entry points**
+
+
+In the `setup.py` file add 'zodbupdate' params into entry_points where is store zodbupdate directives
+
+.. code-block:: python
+
+      entry_points={
+          'zodbupdate': [
+              'renames = mypackage.generations:RENAMED_CLASSES'
+          ]
+      }
+
+
+
+**3) Create a module named** ``generation`` **with the migration directives**
+
+
+.. code-block:: python
+
+    RENAMED_CLASSES = {
+        'mypackage.mymodule MyOldClass': 'mypackage.mymodule MyNewClass'
+    }
+
+
+**4) Run the commands** ``buildout`` .
+
+.. code-block:: console
+
+    $ mypackage/bin/buildout
+    $ webapp/bin/buildout
+
+
+The ``buildout`` command going to install correctly the package and add the new entry_points references in entry_points.txt
+
+**5)  Run the commands** ``zodbupdate``
+
+To finish run `zodbupdate` to apply the changes describe in `RENAMED_CLASSES`
+
+.. code-block:: console
+
+    $   bin/zodbupdate --config etc/zodbupdate-zeo.conf
+
+
+Where `zodbupdate-zeo.conf` is the configuration file to access to the ZODB.