Originally Posted by patelomi
how to remove gallery and how to make quickpic as a default. please explain
It's better if you just Disable it, in that case you can Enable it again if you don't like the change.
To Disable : Go to Settings > Applications > All Applications > Find Gallery > Disable
To Remove: Open any root explorer (like ES File Explorer). Mount the /system partition. Navigate to /system/app, Find Gallery2 (or SecGallery) and you can remove it by deleting it out of there.
Please keep in mind that you can only come back from this by flashing a new ROM, restoring it with Titanium like app or flashing a zip file containing the Gallery with CWM.
Considering you are on stock, the older 4.1.2 and 4.2.2 have Camera app installed with the Gallery application. so removing or disabling the Gallery might also remove the Camera. This doesn't happen after November 2013 builds (MK3), since November Camera and Gallery are two different applications.