You can use the Mixtable spreadsheet app for easy bulk edits in your Shopify store.
In this case, to delete orders in bulk, you can follow these steps:
Once you install and open the Mixtable workbook (spreadsheet), you can add a new Worksheet that is integrated with Shopify Orders data.
Click the + sign to add a new worksheet.
The Shopify worksheet options are broken down by the type of data you want to sync (e.g., Products, Orders). Select Orders and they will be immediately added to your workbook.
Note: You’ll see that when you connect Shopify orders to Mixtable, the data will immediately start populating with any existing data from Shopify into the spreadsheet.
Once that is confirmed and you see the order data in the spreadsheet, select the rows for the orders you’d like to delete, just like you would in Excel - by clicking on the row header and dragging the mouse to cover additional row headers.
Next, right-click on one of the selected row headers (the row header shows the row number). In the menu that opens select the Delete object in Shopify menu option.
You’ll now see a dialog show up, confirming that you want to permanently delete the selected orders in your store. Once you confirm, Mixtable will notify Shopify, asking it to delete the orders. Once the deletion is done, the orders’ data will be removed from your worksheet.
With Mixtable you can also export Shopify orders and export orders’ metafields.