Most users searching for pdf to x_t conversion are actually looking for a way to either import 3D PDF file to 3D modeling tool in order to get a 3D model in Parasolid format, or at least some way to recover the 3D assets from the PDF format. This is actually doable, but not every tool supports such PDF import operation. Also it is unlikely the output will be in Parasolid format, it is more likely it will be some generic format that you will have to further export to Parasolid, maybe even in another software.
In any case, you can find plenty of tutorials and guides about 3D PDF format on the Internet, some useful videos can be found on YouTube as well.
Updated: August 16, 2023