Instructions
Open the "Start" menu and click "Programs." Select "Roblox Studio" from the list of options.
Click the "Open" icon. Navigate to your "My Place" project, highlight it with your mouse and click "Open."
Click "File" from the main toolbar menu. Hover over "Insert" and click "My Decals." This section contains everything you have published to "My Stuff" on Roblox.
Click an object from the "My Decals" window and drag it to your "My Place" workspace. The model has now been added to "My Place." Repeat for each additional object you wish to add to "My Place."
Click "File" followed by "Publish to Roblox" when you are ready to publish your place to the website.