I have a LG optimus black p970 (2.3.4). In Settings->applications, I see many apps that are o KB. I do not know how they got there. There are apps like 'Fire Work', several wall papers for ex , ' Magic Smoke WllPaper' etc. The uninstall buttons for all of these are disabled. How can I uninstall them. Some of them seem to have all kinds of permission on the device.
The apps you are referring to are system apps - that is, they weren't sideloaded; they were integrated into the operating system.
Removal involves having root access and deleting the corresponding (cryptically named) app in /system/app, but I strongly recommend you to stick to a Disable option if available - sometimes system apps depend on other system apps in order to function properly. You might end up soft-bricking your phone if you accidentally delete an important app.