Import Data

Our regional sales director wanted a new task to show up on in all of his sales reps accounts as a new task that appeared on their homepage and as well, listed in the particular account, under open activities.  The import worked, however the owner of the task is not the owner of the account, but rather the person that imported the file.  Any easy way to over write the import and edit so that the task owner becomes the person that owns the account?

In general as well, is there an easy way to roll back an import if nothing else comes in following the import or a simple way to over write?