how-to-setup.md

+Below are step-by-step instructions for setting up the 2D-InSAR VPI ArcGIS toolbox.  
+
+
+## 1. Download source codes: 
+Download this repository to a path of your choice, from now on referenced to as `C:\path-to-vpi-codes\`. 
+
+<!---
+## 2. Update/create PYTHONPATH environment variable: 
+Click `Start`, type: 
+```
+edit the system environment variables
+``` 
+and press Enter. Click `Environment variables...`. If the variable `PYTHONPATH` exists in the list: 
+ - Click `Edit...`
+ - Click `New`
+ - Type the path to where this repository was downloaded (in step 1). 
+
+If the variable `PYTHONPATH` does not exist in the list: 
+ - Click `New...`
+ - In the field `Variable name` type: 
+```
+PYTHONPATH
+```
+
+ - In the field `Variable value` type: 
+```
+C:\path-to-vpi-codes\
+```
+i.e. the path to where this repository was downloaded (in step 1)
+-->
+
+
+## 2. Create ArcGIS Conda environment: 
+Open `Start > ArcGIS > Python Command Prompt` and go to the path to where this repository was downloaded (in step 1), i.e. type:
+```bash
+cd C:\path-to-vpi-codes\
+```
+Then type: 
+```bash
+conda create --clone arcgispro-py3 --name vpi
+conda env update --name vpi --file conda\environment_arcgis.yml
+```
+
+Open ArcGIS Pro, go to `Project > Python > Manage Environments` and activate the environment called `vpi`. Restart ArcGIS Pro. 
+
+## 3. Add the toolbox to your project
+After restarting ArcGIS Pro, go to the catalog pane, left-click `Toolboxes`, click `Add Toolbox` and select the file: 
+```
+C:\path-to-vpi-codes\vpi_arcgis\vpi.pyt
+``` 
+
+The 2D-InSAR VPI toolbox should appear and be ready for use.