How to change from apache to ngnix

Hello,

I see webmin/virtualmin now supports Ngnix . I have 5-6 servers and we want to change from apache to ngnix. Is there any tutorial how we can perform that operation? Or any help at all.
I was able to find just how to change from apache to ngnix on new installed server without virtual servers created but like i mention we have active servers and every server has few virtual servers created.

Thanks