Best way to store downloaded assets in project folder?

I have a big problem.

I has been working with a package that is a modular space ship collection, at the begin to have everyting as I wanted, I moved all the packages that I bought to a new folder called "External" , after make a lots of ship , the autor released a new version of the package with more improves.

So I decided to update the pacakge going to Asset store( in unity) > Download > Update. and unity instead of update the existing package, it just re-imported again to the main folder.

So now I got 2 version of the package and all of the ships that I maded refers to the first package( whicht is the older), so the ships that I made doesn't get the update, I need to do all the work again?=.

Is there a solution to this problem?
What is the best way to avoid this problem for the future?

Thanks in advance

 

I would just delete the old, and move the new into 'external'. backup before of course.
or even just move and overwrite within unity.
There is an Asset on the store (free) called import2folder, I think, I use it works very well.
(I always check the import custom first, if ok, I cancel then use 'import here.'
updating always has its risks of breaking something, be prepared to fix it. or restore backup.

 

Projeny makes handling packages, both external and internally created, easy and nice. But now that you're already 'stuck' with the structure (at least currently):

Do not delete the meta files. These contain the ID that unity needs to hook up all those assets that make up your (ship) prefabs. You'd probably only want to copy/replace all non-.meta files. That should hopefully do the trick.