How to handle errors during a transport with change documents release

You can remove the objects from the request (transaction SE09 --> Object Tab Page). Any changes that you or other users made to the object are not reset. The changes are also no longer recorded by version management which can lead to serious inconsistencies during release upgrade. This should be of no concern in your situation as you are going to do the modifications again anyway.

A better option is the use the Unlock Objects tool which is part of the Transport Organizer Toolset (transaction SE03). This tool allows you to unlock the objects from a specific transport request. All objects in the request end up unlocked. You can use the function 'create versions of the objects' to create versions of all objects when you unlock a change request so that you can document their current version. Functions set to 'released' can be used to set the request to release automatically during the unlock. As of then, you can no longer use this request.