Sometimes we may need to allow user to modify the task properties manually, but unfortunately, if the task is created by declarative workflow through "Collect Feedback" activity, we can only "delete", "claim" or "complete" this task.
Below is the screenshot.
To allow user to modify the task properties manually, what we need to do is quite simple: change the content type settings through SharePoint Manager 2010 tool.
Expand the left treeview to the content type of the task list, we will see the one below.
Clean up the property "EditFormUrl", then click "save".
By the way, if you got exception error when clicking "save" button, please set "EditFormUrl" back to "_layouts/WrkTaskIP.aspx", click "save", then clean it up again and click "save". I think this is caused by a minor bug of "SharePoint Manager 2010".