To be able to open the workshop you need:
- To subscribe to the workshop
- To have the Steam version of RPG Maker MV installed

Open RPG Maker MV (from now on just called MV)
- Go to FILE in the upper left corner
- Select Steam Management
- Look for this workshop in your subscibed projects
- Click LOAD

My project should now open op in your MV
- Press F9 in MV
- Go to common events, and open the second one
- Read the green comments, to understand what I did, and why.

You can also look into the events to see how this can be used in practice.