Remove resolution from issue attributes in bulk

unknown

I am just starting with jira service desk.  I wanted to import all my old tickets from previous system.   I imported as CSV, problem was, the resolution field was imported.  But the resolution field was notes on how the ticket was resolved. 

So now i have over 2500 different resolution types.  Which I don't want.   Is there a way to remove them all at once instead of clicking each individual resolution. 

Mirek

I think the easiest option is to simply use an addon that help do the cleanup in Jira for example - Optimizer for Jira

https://docs.appfox.io/jira-optimizer-dc/Using-Bulk-Actions.27164676.html