Normally Google Chrome save this temporary files inside:
And yes you can delete these manually and you don't need any permission.
So just take a look at these dirs and choose what to delete
Another interesting directory is
Here you find your history , bookmarks , extensions, ....
so choose carefuly what do you want to purge
The bookmark is not really a directory it's just a file. The path to this file is:
The history also is not a file, it's some sqlite3 database file under this path
A simple tip:
will open the directory so just take some time and check all of files found there, you can easily know what to keep or what to delete