Currently Being ModeratedMar 18, 2013 8:20 PM (in response to Sunshine313)
1. If you drag-installed them, just delete them. Otherwise, find and use an uninstaller for that application.
2. Open the Sharing pane of System Preferences and change it.
Currently Being ModeratedMar 18, 2013 8:36 PM (in response to Sunshine313)
Exactly as Niel has mentioned. If it's something you're having a hard time doing, you can also download and install appcleaner - click HERE to download it.
To rename your Macbook - again, as Niel said - see images below: