You can search phrases in the Admin Control Panel for the Text Field contains the words Reaction Score, and then change each instance to your custom word/phrase. (there are several)
If you change the phrase reaction_score to Likes, it will show as Likes on the user profile
However there are many instances so I think even if changing globally from "Reaction score" to "Likes" was possible it would not always end up showing what you want as you may get "Highest Likes" so in that case you may want Highest Likes Score