[NTG-context] Can I use mkii and mkiv side by side?

I have a finished mkii project and I’d like to be able to export it to a format that can be a start for other distributions (such as epub or the like). For this, I get the impression I need mkiv. Now, before I go on trying to move my project to mkiv I have a question. Can I run mkii and mkiv side by side? That is, if I configure my TeX setup for mkiv (I am using MacTeX 2014), can I still fall back to the old setup when I fail? Second, is there some step-by-step instruction to move a project from mkii to mkiv? G