How to update nuget package manager?

Go to tool menu in visual studio and select Library package manager and click Package manager console. If you want to check whether new updates are available for the installed package then, 

PM->Get-Package –Updates

If you wanted to update the specific package, enter Update package with package Id. For example here I am updating jQuery package, 

PM->Update-Package jQuery

If you entered command without any parameter it will update every package installed in your project. For more help enter,  

PM->get-help update-package