another rss "junk" problem

Hi guys,
i’m facing a problem with all my rss feeds that are reporting this error:

XML parsing error: <unknown>:12:0: junk after document element

one of the feed is: https://goo.gl/rjtMiO
and this is the validator response: https://goo.gl/Mrh9iq

my problem is then related to two things: the google plus link and the <script>.

google plus page is the right one (so hacked), but i don’t really understand why is there: in the past i’ve used google author link but i’ve deinstalled it some time ago. Now i really don’t know from where that link is coming.
Do you know how i can MANUALLY correct the feed in order to delete that string? (and also the second).

obviously, i’ve tried to deactivate all plugins but nothing happen

thanks, Beppe