You should not have to delete/redraw the branches, but will have to remove insulation from the affected bundles to enable the revision options.
RMB on the node and select Disconnect Bundle. Then select the bundle you want disconnected (via the +). Repeat if necessary to remove more than one bundle.
Use Merge Bundles to eliminate the node (join the two remaining bundles).
Hope that helps, refer to the Harness user guide for more details.
Thanks James that works.
I've raised an IDEA to ask that this command be availalbe when right clicking on a Bundle.
Please promote IDEA D12876