Need help with a slipped side window string on our 2021 T@G

The white string attached to the lower screen on the side window slipped off recently.  It's not broken, but looks like we need to slip it back over the small black bracket/runner in the lower right corner of the window opening.  Have tried a screwdriver and needle nosed plyers unsuccessfully.  Does anyone know of a specific tool or otherwise have advice to fix this?  Also, looking at the end of the string (in the event it needs to be tightened) in the upper right corner under the corner trim piece, we cannot tell what type of tool would allow release and retightening of the end of the string.  Thanks!