How to change the transition time of Gullu slider. Estimated reading: 1 minute You can change the slide transition time of Gullu slider manually. Here are the manual steps- – Open the file named theme.js from gullu\assets\js directory with your favorite text editor. – Then navigate to the line number 51 and change the default time value with your own time duration. Note: This is a custom task by yourself and does this process at your own risk.