Update Link Types for Multiple Issues
When you're working across multiple projects and teams, chances are there are some inconsistencies between the link types being used.
The following guide will show you how to quickly update all your links to a single, consistent link type using Structure.
The examples below demonstrate how to update link types for an initiative, but the same process can be used for other link types as well.
Step 1: Build a Simple Structure
Create a new, blank structure and add 2 flex items: "Original Link Type" and "New Link Type".
Manually add your parent initiative to both flex items. Note: this should be the same initiative for both.

Step 2: Add Epics
Highlight the Original Link Type flex item and add a Linked Issue generator: +Add | Extend | Linked Items | select the inconsistent link type
Highlight the New Link Type flex item and add a Linked Issue generator: +Add | Extend | Linked Items | select the desired link type

Make sure the Moving items in the struture will update links option is checked for both generators.
Step 3: Update Link Types
Select all the issues under the generator added to the first flex item, and drag them to the second flex item, as children of the same initiative.
Structure will automatically replace all the old links with the new link type.
Need to keep the original links too? When dragging the items, hold down the "ctrl" key (Option key on Mac) to copy the items to the new iniative.
Additional Use Cases
You can also use this same method to:
Update other link types - just edit your Extend | Link generators and the original item added to each flex item
Remove links - include an empty flex item (no Extend generator) and drag your linked issues to the empty flex item - the original link will be removed without adding a new link