Sometimes when you have done your LIDAR scans and need to merge them The best way to do it is with third party free tools after.
Let's start by saying you have your lidar scans in faro SCENE
1. Export .E57 files from Faro SCENE
2. Import into Cloud Compare
3. Select all scans holding control and selecting them in the DB tree of cloud compare. Then goto edit>merge.
4. Save the merge out as a PLY file.
Now depending on how you are going to use the point clouds they may need normals for them to display properly. To compute those:
1. Import the PLY into meshlab
2. Goto filters>normals Compute normals for point sets
3. set neighbor number to 1000 for 5 million point cloud
4. Then save the cloud back out. With _normals in the name so you know what happend.