My Technic Launcher can't uninstall another version of another modpack

[ChronoLati]

So i was going to play on a modpack and it said that the modpack needed a new version of the modpack soo i said no big deal and oh boy was i wrong so i pressed reinstall and then it said install so i pressed it and it said it couldn't uninstall the old version i dont know why does it has to delete the older version so i said lets try to delete technic launcher buuuuuuuuuuuuuuut it was being used by another file (Java) and here i am stuck and cant play my favorite modpack