This is how to decimate a point cloud in order to have smaller files sizes. We will use CloudCompare. Please install in order to continue.
Go to File -> Open the LAS file you would like to decimate
Click on Apply in the next dialog
On the next dialog, click on Yes to All (this won’t change nor modify the real coordinates of the point cloud)
Click on the pointcloud file name on the items section on the top-left and then click on the button Subsample a point cloud
On the Method, select Random
For Remaining Points, this is in function of how much you want to decimate the file.
Example: For half the points, expect half the original file size, and so on.
Now click on the new pointcloud file that was created in the items section on the top-left and click on the Save icon.
When prompted, keep the Highest resolution
Select a destination folder, and save the file. You will see a new file
Note: After this, if you want to import the point cloud into an Autodesk software, such as Civil 3D, you’ll need to convert to RCS.