I have seen at both places, by clicking right on assets > import package > Custom package is available only… Please do let me know the solution. And also at left top assets > Import Package > Custom Package is available only.
@JamilurRehman You’ll need to re-install Unity and make sure you check “Standard Assets” in the Choose Components checklist menu.
Another way of getting the Standard Assets is by simply downloading them from the Assets Store - 1.
I hope this helps answer your question!
Reinstalling was annoying and I didn’t want to do it. For beginners, they might want to know:
Go to this link as of 2018:
Log in to your account.
Click the “Add To My Assets” button.
Then click “Open In Unity”
When unity opens the same page you were just on, except the button now reads “Import”
Click it and import the assets!
@tbriz the link you provided doesn’t work anymore. Can you tell what you typed in the search bar on the asset store website ?