Locate the EX4 file. By default, EX4 files are saved in: [MT4 Installation Directory]\MQL4\Experts\ (for EAs) [MT4 Installation Directory]\MQL4\Indicators\ (for indicators) [MT4 Installation Directory]\MQL4\Scripts\ (for scripts)
Here is a quick guide to understanding these file types and how to handle the conversion. mq4 to ex4