security patch question
 

I am running 3.6.12 Patch Level 2.I do not need any of the newer features of later versions. I am very happy running this older version* but I want to be safe.
What is the easiest way to patch my VB where it will be safe so I don't have to change my templates?

I have many customized templates for Google Adsense which have been very effective in generating income and do not want to have to manually change them just to apply a patch. I know the newer VB has some adsense integration but what I have has been tested and makes me twice the amount of money than the standard adsense integrations.