It's been a real long time since I've played but I'm pretty sure all you need is Heroscape in your workshop and you can just load the map like you would anything else.

If you're talking about getting your units and cards into the map, clicking the ellipsis on the corner of the Heroscape mod will display a menu showing all the individual parts you can load in.

To save you some time though, it's better to pick out your units, cards, dice, and game components beforehand and save them seperately so you can easily copy/paste them into any map later on.

How do I combine this with the base Heroscape mod?