[header] How to make a guy that used to like you like you again [title] Start chatting again. [step] Even if you haven't spoken in a while, talk to him casually to reopen the doors of communication. This will put you in his mind again, as well. 
[substeps] Say " hey greg, nice shirt " when you see him passing you in the halls at work or school. You can even send him a quick text saying something like " even though they're not my team, congrats on carolina winning the national championship.