For an English language video tutorial check here - thanks to Koz4Christ

There are a few things to verify before installing Multiverse-Inventories.

• When running other Multiverse modules (such as Inventories, ensure it's the same version as Multiverse-Core. For example, if Multiverse-Inventories is 4.0.0, Multiverse-Core should be 4.0.0.
• You must have Multiverse-Core before having Multiverse-Inventories.

Grab the jar. Download the Multiverse-Inventories JAR from the release site or grab a dev build from the Multiverse 2 Jenkins

There is NO Zip package available. Multiverse-Core (and MV Plugins) will create default configs for you on the first run.

Place it in your plugins folder like so:

Start your server and enjoy your seperated (and shared) inventories per world!