Data cleansing in Excel

We need someone to help us clean up databases coming from different excel formats and needing to be converted into the masterfile format. Secondly it needs to be cleaned to filter out existing customers from prospect databases. We have two masterfiles and then 4 databases to be merged and cleaned . We have set up a short written briefing for showing the workflow but would also like to spend 30 minutes on a briefing call before the work starts to talk it through