What three changes did they make in the boat before their second return from the wreck?

From the text:

I selected a strong pole for a mast, and a triangular sail, which was fixed to a yard. We made a hole in a plank, to receive the mast, secured the plank on our fourth tub, forming a deck, and then, by aid of a block used to hoist and lower the sails, raised our mast. Finally, two ropes fastened by one end to the yard, and by the other to each extremity of the boat, enabled us to direct the sail at pleasure. Fritz next ornamented the top of the mast with a little red streamer. He then gave our boat the name of the Deliverance, and requested it might henceforward be called the little vessel. To complete its equipment, I contrived a rudder, so that I could direct the boat from either end.