Process like installing Magisk: https://topjohnwu.github.io/Magisk/install.html

How do I switch from the current Magisk to Kitsune Mask and vice versa?
Easy, just do it like when you update Magisk!

Direct Install (Recommended)
Install, open, and then grant root access to Kitsune Mask.
Inside Magisk, tap "Install" and then "Direct Install". If you don't see this, try restarting the app.
Or flash Kitsune Mask from the current Magisk app
Rename the extension magisk.apk to magisk.zip
Open Magisk