As you asked for a detailed post, Here it is !
Note : Updated version of clock face rather than the oreo one.
First of all you have to download the correct version of clock face. After oreo apks I was experimenting pie apks and found that upto this version clockface is working 💥
The version is @
Now install SAI from play store and then enable sign apks from settings.
Now select the apk and start installation.
After the installation is complete open it using lock screen in settings. Shown below 👇
And the result is :
Hope this one is helpful.
Performed on my galaxy M01.
