Its very easy,really! :) You just go to the "Profile" tab right beside the "Home" tab at the top of your screen.
Click on "Edit Profile" which is written inside a red button at the top of the page.
After that Google+ will ask u to click on the part of the profile you would like to edit!
So then just click on the small link below the profile picture which says "Change Photo".
Clicking on "Change Photo" will take you to a page like this :
Just click on "Choose File" and upload a file from your computer through a browser window which should look like this :
Browse through the files on your computer to find and highlight the wanted image. After the image has been highlighted by clicking upon its name once, just click Open and your image shall soon be uploaded. It may take some time in case your images are big in File-size.
While Google+ works on uploading your image a screen like this will be shown :
Please have patience while it completes the task.
On completing the uploading process, it will pop-up a screen which is basically a Thumbnail Chooser similar to the one you can find on Facebook but the difference being here you do not choose only the Thumbnail, but ALSO the profile picture will have to selected as a square image. So be careful while you choose the square image by pushing the square block around and dragging the corners like this :
And there you have it : a new perfect profile picture as easy as it gets! :)
