There are a number of really helpful sources of information on anonymising research data for sharing.

• UK Data Archive (UKDA) advice on anonymisation of quantitative and qualitative data: http://www.data-archive.ac.uk/create-manage/consent-ethics/anonymisation
• UKDA presentation on anonymisation techniques to enable data sharing: http://www.esds.ac.uk/news/eventsdocs/consentdec09vvde1.pdf
• University of Edinburgh provide explanation and some useful examples: http://www.ed.ac.uk/schools-departments/records-management-section/data-protection/guidance-policies/anonymisation
• Information Commissioners Office code of practice on anaonymisation: http://www.ico.org.uk/Global/~/media/documents/library/Data_Protection/Practical_application/anonymisation_code.ashx