Question: how to make epw file?
Answer: Open your EPW as a CSV in Excel.
Make the desired edits, such as plugging in your weather station data. ... 
Save the file as a CSV. ... 
Then I open the files in Textpad or Notepad and combine the header and body. ... 
Then I manually change the file name from . ... 
Then the EPW file works in EnergyPlus.