Before you can make any changes on the messenger the messenger zip file must have been extracted 
and imported into the android studio. 

To extract the folder, you right click on the folder and click on the extract all options then extract.

To import the folder into android studio

1. Open android studio

2. Click on File Menu

3. Then click on Open.., A box would pop up to enable you track and select the extracted messenger folder.


The messenger folder won't appear as a folder but as an android project as shown below.