How can I get this song into RS14?

You cannot get it officially anymore. You need to own Rocksmith 2012 and buy the import tool dlc. 

In this thread https://customsforge.com/index.php?/topic/75814-eye-of-the-tiger-survivor/#comment-395621,

you said it showed in RS1. I am assuming that you own RS1 then. I shouldn't assume, but that being stated IF you already own RS1 you have this song. If you purchase the import tool, you can import most of songs from RS1; https://store.steampowered.com/sub/32387

If you check out this link it will tell you what songs do not import: https://theriffrepeater.com/rocksmith-2014-setlist/rocksmith-setlist/

If you do not own RS1, I've already answered that question. Review your prior posts. You can create it yourself for yourself and only yourself.

Eye of the Tiger is RS1 DLC

 

Use Somebody is part of the RS1 Import