How to add Fibre into a rabbits diet if it doesnt eat hay!?

Seems like a fussy eater. But we all have our dislikes. Even animals 0.o. Any fresh fruit/vegetables are suitable for a herbivore such as your rabbit. Try lettuces, carrots, apples, spinach leaves, pears..etc. You don't even need to cut it up small. Let him enjoy the challenge of trying to chew it down. Luck.