You can get the trial by going to the developer’s website to enter your email and you will get a link to download the free trial version of ZBrush. ZRemesher has been updated in ZBrush 2019 to have better support for hard surfaces models, with a focus on re-topologizing meshes resulting from Live Boolean operations or imported from CAD 3D packages.
Hard Surface automatic retopology taken to the next level. However, this free Trial may not be used for commercial or other for-profit purposes. There are no watermarks or feature restrictions of any kind. With the ZBrush 2018 free Trial you will have unlimited use of all the features found in ZBrush 2018 and complete freedom to evaluate how it can fit your needs as an artist.