To Install tOpos simply close Rhino and copy tOpos.gha and fize dll files (tOposCore.dll, CudaSparse.dll, CudaBlas.dll, ManageCuda.dll, cublas_64_80.dll, cusparse64_80.dll) ,and the three dll files into your grasshopper components folder.
Copy all files from UserObject subfolder (DEnsPreview.ghuser and Element Data Previe.ghuser) into your grasshopper user objects folder.

Note:Sometimes Windows is blocking files from internet. Check if all files are unblocked by right clicking on each file => properties => If file is blocked on the bottom part of properties panel will appear "unblock" checkbox. By ticking it and applying changes file will be working correctly. 
Without this operation tOpos may not load at all.

Restart rhino and grasshopper and the tOpos toolbar should appear.
This version of tOpos requires 64bit rhino (5.0 or 6.0) and won't work with 32bit Rhino.

Current version of tOpos require NVIDIA graphic card with Cuda Computation Capability (cc) higher or equal to 3.0. Here: https://en.wikipedia.org/wiki/CUDA#GPUs_supported you can check if you generation of GPU is compatible with tOpos. Also check if you drivers are up to date (do not use Windows Update drivers!) Install newest drivers form NVIDIA website. Your graphic card drivers version need to be at least 376.51.