The reason why you cannot remove the app is because you must remount the /system folder with write permissions. think of it as a last safety lock before you get to the actual stuff on it.
If you have the evo-recovery folder, then use adb-windows. Connectbot allows you to do this on your phone without a pc but it requires that once you are logged on, to type
su to get superuser access (root).
To mount the /system folder with write permissions you can either use adb OR connectbot. Once you have logged in type:
Code:
mount -o remount,rw -t yaffs2 /dev/block/mtdblock4 /system
At this point you will be able to permanently remove files from the /system/app folder where most of the Sprint stuff is located. You can use astro (GUI), adb (CLI) or connectbot (CLI).
Be very careful with what you remove!! Once you remove something there is no UNDO for it. You'll have to re flash
Once you are done, you should close the filesystem again, to do that you use again adb or connectbot and type:
Code:
mount -o remount, ro -t yaffs2 /dev/block/mtdblock4 /system
Obviously, your phone must be FULLY rooted (2/2)