Edit Category – Copy out text of Description / SEO fields in to a text editor (This can/will be lost in the conversion)

_Setup redirect rule for old category
eg to Forward http://onthewight.com/business/solent-lep/ to http://onthewight.com/about/solent-lep/

Use:
Source as ^/business/solent-lep/$
Destination as /about/solent-lep/

_The conversion
Enable Taxonomy Converter plugin

Select ‘Convert’ and tick ‘Tags’
Pick the Category that you’re looking to merge / change to a tag
Click the Go button at the bottom of the page

Edit the destination Tag – Include all of the text you copied out of the previous Category. Save

Disable Taxonomy Converter plugin