Hi,
You really can't just leave it in there, you should take it all out before you install your new expansion packs, just moving it to desktop or whatever is ok for the moment.
If you have any hacks or mods in your game you will have to check they are compatible with your new expansion packs and download the updated version for those expansion packs.
Most of your objects, skins and such should work with the new expansion packs, some exceptions apply though like custom computers, bookcases - they will not have the new option available in the university expansion pack.
I also recommend installing your downloads back in, in sections to check for conflicts.
Hope this helps.
