Talk and patience, lots of it, you must find out her apprehensions and work on eliminating them. convince her its not wrong but widely accepted for women to enjoy sex with black men, in fact it's very common, just look on the internet, tell her that you would never condemn her or look down on her for considering or fantasizing about sex with a bbc, tell her thats your goal, her fantasizing about sex with a bbc. Encourage her as she will probably have reservations as its a life changing decision for her.
She may have history or family opinions to overcome or negative influences affecting her, so communicate alot and often, really listen to her, make a real effort to understand her concerns, her worries to having sex with a bbc, work on getting her comfortable with the idea of interracial sex, emphasizing how exciting and satisfying it could be for her,giving her gratification she's never experienced before. How you'll support her one hundred percent and stand by her if she decides to explore sex with a bbc, incresse her exposure to bbc sex by watching bbc videos to peak her interest and stimulate her curiosity,
Read stories of bbc and other couples experiences on the net, how rewarding and stimulating it is for the wife/girlfriend, How exciting it would be for the both of you., remind her the greatest regrets come from what you didn't do rather than what you did do! Tell her this is a sexual experience she should investigate, you're going to support her every step of the way, it be like a first date all over again but with phenomenal sex, use bbc dildos in your sex play, keeping her mind engaged and her desires aroused, assure her its an amazing opportunity she absolutely deserves and should try at least once. Convince her it may become her biggest regret she didn't do it sooner, but don't push to much or to hard, let her dwell on the her thoughts and let her curiosity and desires develop on her own.
Where the mind goes the body follows, if she doesn't get it right in her head then there'll never be a bbc in her bed! Bring up the topic during sex when she's aroused but never push to hard as that'd push her away and build resentment, slow but patience is the rule, its gotta be her choice her decision, to much pressure will only defeat your goal, keep her interested and curious but on her terms. Try to keep it fun and enjoyable maintaining a positive attitude. It's gonna take time but a worthwhile journey. Let us know how you're doing from time to time It truly is a fun and exciting journey, one many women find most pleasurable, enjoyable and totally gratifying.