Start with the basics. It is not clear what you want to do and why or what is happening.
This forum is for 65lb towers, not notebooks. Though you may want the Mac OS forum area itself.
Direct you to the proper forum for MacBook :
MacBook Series Forums
Failing software? what are you trying to do and have you used Safe Boot and Recovery Mode.
General purpose Mac troubleshooting guide:
Mac OS X: Starting up in Safe Mode - http://docs.info.apple.com/article.html?artnum=107393
What is Safe Boot, Safe Mode? (Mac OS X) - http://support.apple.com/kb/HT1564
Creating a temporary user to isolate user-specific problems:
Identifying resource hogs and other tips:
Starting the computer in "safe mode":
To identify potential hardware problems:
General Mac maintenance:
Normally you don't uninstall the application unless it is not compatible.
And I strongly recommend you use a couple types of backups.
To uninstall depends on the software installer.
If it had an installer, then you need the uninstaller to remove all the parts. That is usually on the same dmg that you used to install, or it might have been installed onto your Mac by the installer. See the company website to find the uninstaller or the instructions.
If it was Drag and Drop, just drag the app to the Trash.
If it was App Store, go to Launch Pad and hold down the Option key. A small X will appear on the icon. click that.