You should never have to reboot a linux system to get a filesystem remounted. All you need to do is becomeroot in the terminal and unmount (umount command) the filesystem and then remount it read/write (option rw) with the mount command. If it is busy so you can't unmount it, you can always do a remount=rw command, in which case it will not be unmounted for real, but the mode will be changed to read/write.

I know that the man-pages on the tablet itself are non-existant, but if you google for them, they are easily found.

Just a tip to avoid rebooting too much - rebooting is something you've learning in Windows-world. No computer should ever require rebooting, unless you actually need a new OS kernel. Imagine how much time you waste in your life waiting for reboots...