1) Download the MQ4 (or *.ex4) file into your

C:\Program Files\MetaTrader 4\experts\indicators folder

2) Close your MetaTrader application (assuming it's currently open ... Ignore this if the application hasn't been launched)

3) Launch your MetaTrader application

4) On the left hand side, look for the "Navigator" window

5) Under the "Common" tab, look into the "Custom Indicators" directory

6) Locate the indicator which you have just downloaded into the folder stated in Step 1

7) Drag (Click and drag) the indicator onto the chart