This is going to depend on a couple things:
1. Do you allow deletes? If not you can enable them in a few steps.
2. What is your storage device? If it is a WORM device you will have some problems.
If you allow deletes and the storage device allows deletes then you can give a user permission on the archive and they can use the WebApp search to find the items and delete them.
You may wish to document the delete and the reason why in case of any questions arise in the future.
regards,