Just trying to help out the noobs.
1. Click the download link, when the download menu opens, hit "Open".

2. Once it opens in WinRAR (if you don't have it, you can get it
Here) click "Extract"

3. Now choose the main folder of your Blockland

4. Hit ok, let it overwrite if it must, start BL and hit "Start Server", hit "Add-Ons", find the mod you installed...

5. Then tick the box next to it/them to enable it/them, after that click done and hit launch game

6. Now place a brick (or 2, depending on the mod), press q and select the wrench, hit the brick and under "Items" select your item and hit done.

Hope I helped someone.