This article will tell you what the recommended steps to perform before deleting Xray

Step-by-step guide

1. Bulk select the Xray issues
2. Delete them
3. Run the Integrity Checker (Jira Administration - Manage apps - Xray):
   
4. Do a Jira Re-index (Jira Administration - System - Advanced - Indexing:
   
   
   
   

   Link for related documentation
   
   FAQ#WhathappensifIuninstallXray?