First of all it's necesary activate the Processing plugin that allows the processing options. (Plugins > Manage and install plugins... > Processing)

If you have activated the Processing Plugin and the Batch Hillshader plugin does not detect it, restart QGIS

# LASTools Library:

    Read the following lines that describes the steps for install and activate LASTools Library. 

    First of all, please read the LASTools License, you cant see at <https://rapidlasso.com/lastools/>
    and download the installer from the LASTools Library web site (<https://rapidlasso.com/lastools/>).

    Once the library is installed, open the LASTools folder, open the QGIS_toolbox folder and follow the steps 
    that are described in README.txt file.

    The last step is to activate the library in QGIS. Open QGIS, go to "Processing options" in menu "Processing > Options".
    Next expand Providers, Tools for LiDAR data, check the Activate option Check Box and set the folder of LASTools installation.

# FUSION LDV:

    Read the following lines that describes the steps for install and activate FUSION LDV.

    First of all, please read the FUSION LDV License, you cant see at <http://forsys.cfr.washington.edu/fusion.html>
    and download the installer from the FUSION LDV website (<http://forsys.cfr.washington.edu/fusion.html>).

    Once the software is installed, activate it in QGIS as like as LASTools Library. Open QGIS, go to "Processing options" 
    in menu "Processing > Options". Next expand Providers, Tools for LiDAR data, check the Activate option Check Box and set 
    the folder of FUSION LDV installation.