you can remove some applications by finding there updated version on nokia store
ex. if your cell has a pre install facebook it will show as a system app and u can't delete it, move it an update it ..
so solve it go to nokia store on phone and search for facebook there and install it will download the new version and remove the system 1 and move new version to memorycard where u can move it,update or even delete it.
and you can't use the space of the app in phone
hope i had help U .. sky~Aakash