*cough* Did you even read the post right before yours? *cough*
Anyways, to delete the things you don't need won't free up much RAM since every app, picture, and language is stored in the Archive. If you still want to delete them, Press [2nd]>[+]>[2]>[1] and delete anything you don't find useful.
Although you can't break your calculator doing this, you can break some games if you just delete whatever you don't recognize. I recommend looking for the app names and languages you never use and delete those. If you have any Matrices that you don't need, I suggest deleting those too. Leave everything else.
There are some great tools that solve these issues, but you're going to have to lift your eyes a little higher to see them and their links.
I also suggest upgrading your OS to OS 5.3 as it allows you to run every program from the Archive, and ASM programs without the Asm( token.