Restore in PD from the zipped file

Hi,

I need to deploy a package in PD. Business is concerned that I need to rollback if later something is not working.

I read few documents and understand that:

1. Login to PD910

2. Save the object

3. Deploy the project to PD

4. If rollback is required, login to PD910, and restore from the par file (zipped in step2)

My questions are:

1. After the object is restored, and checked-in, do I need to build and deploy the package containing the restored objects or just checkin is enough.

2. Please also check if I am missing any step in the backup/restore of objects.