How to replace all info downloaded from amazon easy

[Porto]

With this new policy from amazon I'm wondering if anybody have a suggestion to find a fast easy way to replace the info downloaded from amazon for my DVD collection with some other sources like IMDb or any other.
My desire is to know how to keep as similar as possible my collection in my computer and my mobile device, i. e. picture, actors, year, format, etc.
Probably is not a big DVD collection (400+) but maybe 90% of my info I downloaded from amazon. It was by default the first source and I never thought to try a different one just because my ignorance.
I presume one way is to delete the movie and then download the info again from a different source but that mean to invest several hours to do it.
Any sugestion?
Thanks

[sjk]

I think the easiest way would be to select and edit multiple entries, clear out any fields associated with Amazon (I'm not sure exactly which ones they are), then use Advanced > Get Advanced Info for Selection > Site to repopulate the cleared fields (as much as possible). If you use IMDb then having its numeric value (whatever that's called) already filled in for entries will ensure Get Advanced Info for Selection finds the correct titles. I'd make a backup right before doing it so undesirable "bulk change" results could be easily reverted.