Unfortunately this can't be done. The 2GB internal is actually the RAM and is where the apps actually run and will be occupied as you stated. The 25GB is like the hard drive of a computer. The 25GB is only for storage of apps and data. Try running an app that let's you force close apps (Clean sweep or 360 security) and has the added bonus of cleaning the junk off of your device. I run 360 on my phone and it keeps it running really fast.