Below are the steps the remove workflow manager completely. I have seen many instances where we had issues during installations.

Removing Workflow Proxy

1. Central Administration à Application Management à Manage service applications
   
2. Select and click delete the “Workflow Service Application Proxy”
   
3. Click Remove Data check box and click OK.
   

Removing Workflow Manager Farm

1. If you have more than one workflow manager machine. Remove each node from the farm using the
   
2. Click Start à All Programs à Workflow Manager configuration à
   Leave the Farm
   à Click confirm button.
   
3. Repeat step 2 on every other WFE.
   
4. Open SQL Server Management Studio Delete all the following databases (All previous)
   
   1. 0x_WfManagementDB
      
   2. 0x_SbGatewayDatabase
      
   3. 0x_SBContainer01
      
   4. 0x_WFInstanceManagementDB
      
   5. 0x_WFResourceManagementDB
      
   6. 0x_SBManagementDB
      

Removing Workflow Manager Binaries

1. Open Control Panel à Uninstall a program à Updates
   
2. Uninstall the CU of Service Bus from Updates
   
3. Uninstall the CU and updates of Workflow Manager
   
4. Click on Programs from left
   
5. Now Uninstall Workflow Manager 1.0
   
6. Now Uninstall Workflow Manager 1.0 Client
   
7. Now Uninstall Service Bus 1.0
   
8. Now Uninstall Windows Fabric
   
9. Delete the following folders (if Exist).
   
   1. C:\Program Files\Windows Fabric
      
   2. C:\Program Files\Service Bus
      
   3. C:\Program Files\Workflow Manager
      
10. Delete the following registry key (if Exist).
    
    1. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ServerManager
       
    2. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Service Bus
       
11. Restart the server
    
12. Repeat step 1 to 11 for all workflow manager server.
    

Uninstall the workflow Manager Client

1. Open Control Panel à Uninstall a program à Right click on Workflow Manager Client
   
2. Click Uninstall.
   
3. Repeat this process for servers that has client installed.