The how to adjust odd frame.

So I dove head first into making my very own caferacer, I've never done anything like this project but I'm not one to be scared off by difficult new things. That said so far I've figured most of the things out by myself or google. But I cannot for the life of me find any good info in how to adjust a frame to fit the seat in a proper way. I have a Kawasaki z400 Ltd, not the best model but I work with what I got. As seen in the picture below I have a really hard V shape currently and not sure how to straighten it out to get a proper line with my tank.. https://imgur.com/a/PptuzwLAny advice? Thanks! via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/d9fjcu/the_how_to_adjust_odd_frame/?utm_source=ifttt