If your org is ready for Lightning ready, As an admin, How to Hide Switch to Classic option to profile level
Click on Setup
In Administer, expand Manage Users
Click on Profiles
Select the Profile name
Click Edit
Go to the Administrative Permissions
Enable
- Hide Option to Switch to Salesforce Classic
- Lightning Experience User
Click Save
Notes
This possible only the Custom Profiles
To Enable the “Hide Option to Switch to Salesforce Classic” then Lightning Experience User is a mandatory