Openvpn / pihole - change administration link

Hi
So, I've had openvpn running on a raspberry pi for over a year with no problems. After some braining I concluded that I also should run pihole on the same raspberry pi. After all it's "just a DNS resolver". Both are running great together on the raspberry.
But, I can't administer openvpn because they both use "<IP of raspberry>/admin", and because I installed pihole last, well I can now only administer pihole.
So, how do I make one of them use something like "<ip of raspberry>/admin2" ?

Thanks