The official SAP Help Guide for Lumira at http://help.sap.com/businessobject/product_guides/vi01/en/lum_121_user_en.pdf walks you through the steps.
First you have to go to your users file – for example c:\users\<user name>\.sapvi and you will find files named enrichment_suggestions.version number.txt
I have filenames going back to enrichment_suggestions.1.17.0, with the latest being enrichment_suggestions.1.21.0
So I thought I would try it out – as an example, Lumira wants to auto-enrich the field name “SUBMISSION_TITLE” to be a measure when it is really a dimension.
You can see from the above that Lumira wants to consider SESSION_TITLE to be a measure.
I open up the rules file using Wordpad
In the above I have added SESSION_TITLE to the rule to hide for measures.
I save this change and re-launch Lumira Desktop:
You can see from above the rule worked as now SUBMITTER_TITLE is no longer a measure.
I am looking forward to learning more at BI 2015 next year.