Update install_and_test.md

install_and_test.md

@@ -35,14 +35,15 @@ can re-install a python module in **editable mode (use -e in pip install)**. For
 git clone ssh://git@git.ia2.inaf.it/hotwheels/timestep.git
 cd timestep
 # very IMPORTANT the -e will install in editable mode
-# so you can change the module code and effects will take place
-# without need of uninstall and re-install
 pip install -e . 
-# edit the file of your chise, for instance ./hotwheels/timestep/cosmo.c 
-cd ..
-python -m hotwheels.checkup hotwheels #now the tests are run with the new ./hotwheels/timestep/cosmo.c 
+#
+# edit the files of your choice. Edits will take effect
+# without the need of re-installing the package
+#
 ```
 
+
+
 # Run tests
 
 To run the C and python tests of the installed `hotwheels` components, run: