Read the patch note. It tells you exactly what to do there.
Whenever you apply a patchset or PSU, you really need to read patch note and follow it exactly.
The database patch note is here:https://updates.oracle.com/Orion/Servic ... u=15962803
Just work your way through the document. I think the only thing of note here is that you are using ASM, which means you will have a Grid Infrastructure installation. the patch note says,
"If you are installing the PSU to an environment that has a Grid Infrastructure home, note the following: Grid Infrastructure PSU 18.104.22.168.6 Patch 16083653 should be applied to the Grid Infrastructure home and Database home using the readme instructions provided with the patch."
So you need to patch the GI with the specified patch, before moving on to do this database patch.
There are no shortcuts or clever things you can do with these patches. Every time (and I do mean every time) I have to apply a patch I follow the patch notes exactly. Without deviation!