Rocker gasket for W204.

[OmahaKnot]

Hello everyone.
I hope you're doing well. Good weather for a bank holiday thus far.


Perhaps I might use some assistance.
V204 C220 CDI 2013 2.1.

Around the injectors, I've seen oil seep in. The rocker box gasket, according to my dad, is the culprit. Since he has made some changes to the e300 and did mention anything else... it may have been the sister's 204 07 plate.
I've been trying to find some sort of guide or tutorial online so that I can at least understand what my dad is saying and be of assistance when I go down to help out.

I was wondering if anyone has any advice on how to replace or remove it.
Specify the gasket type you think will work best. Not necessarily the greatest, but cheap and ugly or pricey.

Much obliged.