Ineed on how to do this step by step.

So.. hmm notice the picture below

the inscribed angles of A and D, are really intercepting the same arc of BC

that, means that A = D, and you can see there, what angle D is anyway

where the segments DB and AC intersect, they create 2 vertical angles
namely the triangles made by all chords, are similar, so their angles are the same

so if angle A = D, then angle C = B