Step 1 >> Go to on “Help” and click on “Select Eclipse Marketplace”
Step 2 >> Search for testng and hit enter
Step 3 >> Click “Install” for “TestNG for Eclipse”
Step 4 >> View check boxes are selected then click “Confirm”
Step 5 >> Accept license and click on “Finish” tab.
Step 6 >> During installation a warning message comes but to continue click “OK”
Step 7 >> For complete installation there will be a pop up to restart. So just restart it.
Step 8 >> To know it is installed or not. Just go to “File >>New>>Other” then there get a folder is created with name of “TestNG”.