multisite subdirectory redirect to another multisite

We have a multisite – http://yourlifeassist.co.za with multiple subdirectories (sites).

The – http://yourlifeassist.co.za/primecare site has changed it’s name but they want to retain the ‘old’ URL for legacy users with an automatic redirect to the new site landing page –

http://yourlifeassist.co.za/groupfive.

Both sites;

http://yourlifeassist.co.za/primecare

and

http://yourlifeassist.co.za/groupfive

are present in the multisite.

What is the best method to achieve this?