In order to use A/B/Multivariate testing, your Sitecore website solution needs to support the idea of page components.
Each 'component' is a sublayout that pulls its content from a datasource item. The 'test' is essentially just swapping the datasource for the sublayout so you can test different content, much like you would setup DMS personalization.
If your content is not structured into page components, you cannot execute the tests. There are several companies out there that will audit your build to determine your solution's DMS-readiness, and you can probably get them to fix up your build to support DMS as well.
If you will be doing it yourself, here are the basic steps:
- Split up your page layout into sublayouts. At the very least, the portion that you want to test should be in its own sublayout.
- Create new component templates for your content that will be displayed in these sublayouts. This will be the data for your datasource.
- Create new content items from your new component templates to represent the data variations you want to try.
- Update the code for your sublayouts to access the Datasource property of the sublayout to find the content Item, instead of using Sitecore.Context.Item
- Using Page Editor, configure your page component datasource to pull from one of your new component content items.