1. The new/changed requirement(s) is(are) identified.
2. The BA enters the new/changed requirement in a Change Control form
3. The BA evaluates the impact on the requirements – identifies the one to be deleted, changed or added.
4. The BA enters in the Change Control form the details from the requirements impact analysis.
5. Representatives from the Development and QA team, this could be Lead from each groups, analyze the Development and QA impact of the change and enter the details in the Change Control form.
6. The PM enters details about the impact on the project budget, timeline, etc. project metrics.
7. Then the form is brought up to the stakeholder’s attention, in the Change Control Board for example, where they decide if the change will be implemented.
8. If the change is approved the BA has to update the Requirements document and the Engineering and QA implement it. If the change is rejected, the change control form is filed for future reference.
9. The updated Requirements document becomes the new baseline.

Technically this isn't actually change management.  It is called change control.  Vessela has summed up this concept well.  For a more information you should google the PMBOK.pdf (You are looking for the PMBOK 3rd edition.)

The phrase change management often confused with change control, however in the industry jargon change management is usually referring to to activities associated with business process, organsiational redesign and culture change activities that often go with a new IT system.

Here are two useful references for you to investigate change management further.  The first is from my blog Better Projects and looks at change management

specifically for project professionals like BAs.  The second is a blog specifically on the topic and relevant to all change agents including consultants and operations managers.

Better Projects 1, Better Projects 2

Change Management Blog

To answer your interviewer I suggest you ask which version of change management/control he or she wants explained and then dazzle them with your broad knowledge of change theory.

Good luck.