If you are the one who posted the Job, then just login to the platform and click on the job. In the following screen, click on Update job.
Here you can update only the basic details shown in the below screenshot.
If you are not the one who created the job or if you want to update details other than the ones shown in the above screenshot follow the steps given below -
Step 1: Go to Jobs or internships through the the admin panel.
Step 2: Click on the title of the job opportunity you want to edit.
The above dashboard displays a list of all job opportunities posted (both by users and admins). You can use the search bar on the right to find the job you want to easily.
Step 3: The page that appears when you click this is the individual job detail page. Edit any details that you want to change and then click Save .
NOTE: At the bottom of the respective job detail pages, you'll also find a list of applicants, and the details they have submitted (such as the submitted resumes) - You can download them from here.
The procedure is same for internships as well.