It could/should probably be easier- but here's how.
First you must find the friend- either by username, email or location -
http://www.oobgolf.com/golfers/search.php
The search is a little clunky- I'd suggest asking for a username and searching that way in Keywords. Sometimes less is more with this search. If you type just a username or email address you'll be golden.
Once you find the user- click into their account- and then at the top left under their avitar you can click "Add to Friends." That's all you have to do - then it is on them to accept. If someone has requested your friendship- you'll be notified by email and on your My Game page.
Hope that helps.
_________________
Kickntrue-
Duffing since 1993