How do you make stuff free in roblox

Select what you want to make into a model, press CTRL-G to group the items.

Go to the File menu and in that dropdown there is a choice: Publish Selection to ROBLOX

Use that to create the model. A box will appear, it will have three choices: Create, Update, Cancel. Choose Create. The box will change, at the top you can change the name of the item, in the middle you can type a description and on the bottom you can check the box to make it Public Domain (Everyone can take) Then press Publish (Or Cancel if you don't want to upload.) And then your model will be in your "My Models" section of ROBLOX.

Hope this helps,
Grunty