Your pepper has a stem, a top from which the stem extrudes, and lobes, fleshy bumps that run from the stem end of the pepper to the other end (where the blossom used to be).

Start by cutting around the top deep inside the pepper, to free the core.

Then cut one lobe out.

Cut the whitish "veins" away from the lobe and tap, tap, tap the lobe on the edge of a bowl or the table to get the last few little seeds to fall out. (There's nothing harmful about the veins and seeds, they just don't have much flavor.)

Continue with the other lobes until the pepper is completely dismantled.