@anitha9736 going by your pictures it looks like the front bezel and possibly the hinges are giving you issues. First, I suggest you download the service manual for your computer, [https://dl.dell.com/topicspdf/vostro-14-5401-laptop_owners-manual2_en-us.pdf|from here] That'll show you how to remove the complete display assembly.
To work on the display assembly, you can follow [https://www.youtube.com/watch?v=KRcRbGHXoPQ|this video] starting at about 12:10 to see how the bezel comes off etc. There could be slight variations between the Inspiron and the Vostro, so work slowly and keep your eyes open for those variations.