Default [Q] Cant Uninstall Launchers on Kindle Fire HD 7"

So I rooted my kindle a couple weeks ago and it was working good, but it got slower and slower. It wouldn't let me do a bunch of things so I finally just reset it to the defaults. Everything was wiped, which was fine, but I still have magic locker, no lock, nova launcher and like three other launchers on it. I opened ES File Explorer and found the files and tried to delete them but it said it cant "Read Only File System". Whenever I turn my kindle screen off it goes crazy with magic locker and the other launchers. How do I uninstall these?