mobile

I'm using micromax unite 2 a106. It has 8 gb of internal memory, of course of which 1 gb is available for installing apps and 5 gb for keeping the media stuff.Whenever i try to install some new apps or update any app its says insufficient memory. Is there any way so that i can use those 5gb of internal memory to install apps like may be by changing the rom etc. Pls suggest me something.