I'm looking at the pics of the tear-down guide
as I write this, and can assure you that it's going to be really difficult. You can find screens and digitizers on ebay because they are from a different manufacturer (Samsung) and a lot of pople need them.
However the audio port is part of the camera PCB, which is a custom HTC part. The only ones who have access to that part are the repair centers that work for HTC, and to my knowledge they aren't selling those parts.
My suggestion would be to remove whatever is in there. Use a stick that could fit, with superglue at the end. Be careful not to hit the sides with the glue tho. If that fails, you can always open up the phone (with that guide as a reference) and remove the camera PCB. That should make it easier to remove the object.