Grand Hyatt-> Bund via ferry
Time: 10 minutes walk, a ferry ride, and Y2 for the ferry ticket.
Walk out the front door of the hotel to the street, turn right and at the first street you come to, turn left. Walk one block (you will pass a golf "club' with a driving range on the left side of the street). At the first street, Liujazi Circle road, turn right and walk to the end, about 2 blocks. Turn left and about 200m down the road on the right is the ferry terminal. The ticket booth isn't that obvious but you pay them Y2 and get a poker chip which you insert in the turnstile to ride the ferry across the river.
At the other end, you come out in the middle of the Bund promenade, walk up a flight of stairs to get to it. Go north if you want to go to the Bund tourist tunnel to return to Pudong.
There are numerous ticket windows selling attraction tickets on the promenade but they all seem to be selling them at full box office price so there is no reason to use them. And if, like most visitors, you arrive in China desperately needing a cheap Rolex knockoff watch, you will be given numerous opportunities to buy one along your walk on the promenade!