How do I remove a broken piece in the headphone jack?
How do I remove a broken terminal in the accecories port of my Z799VL?
If the headphone socket is internally damaged it cannot be repaired, it needs to be replaced.
Here’s a video that shows the teardown of the phone that may help to get access to the headphone jack.
I cannot find a replacement spare part online but thought that this may be an option to consider as a donor parts phone, given that the price is OK where you are.