junior transfer

Why were you not involved in greek life at the previous school? If you are coming from community college-- why did you choose community college? COB may be a better choice depending on why you are waiting to go through recruitment

How do I go about COB?

I would NOT advise COB. Go through formal. If you don't pledge, you can still do COB.
First, being a junior will definitely hurt you.
Second, how are your grades? If they are excellent, that will help a lot. If only fair to good, that will be another mark against you.
Third, work those sorority connections! Make sure your legacy connections write recs for you and make sure they explain why you are enrolling late.
Fourth, get recs for EVERY group, not just your legacy groups.
Fifth, keep an open mind. You may very well get dropped by your legacy groups if they are top tier, in-demand sororities. You are more likely to get a bid from a "smaller, lower tier" group. Ask yourself - do you want to be in a sorority? Or do you want to ONLY be in certain groups? And be realistic. Anyone who will reject all but sororities A, B, or C is bound to get disappointed.
Keep an open mind, get recs, dress sharp, and smile! Good luck!

I remember talking to a girl during recruitment this last fall and she was a junior who was a transfer from a community college. She was awesome (I don't know what her grades were like) and although my sorority didn't keep her, I do know she ended up getting a bid and pledging somewhere!
Just keep an open mind and be yourself (:
If it's meant to happen during fall recruitment it will and always know there is COB!
Good luck!

I know a few girls who got in as juniors! I think you should definitely give it a shot!

I rushed as a junior! It's a little bit harder, because a lot of the questions girls will ask you are ones tailored to freshmen, and the cuts are pretty brutal. Also your Pi Chi group may be a little stiff towards you/bonding with the pledge class is a lot harder; if you're of age you have to wait to go to bars until after initiation. I had two sororities left on pref, though, and I love the one that I'm in! My big also rushed late, so she was a junior and helped me get to know other juniors in our sorority, which helped immensely. It's not an easy process, but it's definitely worth it, but I would highly, highly recommend COB.