Looking to do OP levels help?

Hey I’m looking to do the OP levels on my Psycho and Gunzerker (5th/6th characters). Couldn’t see a dedicated topic for this and It’s proving fairly difficult after these are not my mains - plus it’s been awhile since I played the 360 version, so I thought I’d try my luck in the forum. If anyone is looking to them or help out at any time my GT is andy2608