What can I do with an overgrown palm tree ? It's tall and bending over

Sorry, most palms only grow from the top and many can live for 50 to 100 years. Since you say 'it' I think you have just one trunk. You can prop it up with an 'H' shaped brace (place the cross piece up high in the 'H') or cut it down and start over with a new plant. The bottom 10 feet or so of the trunk can be saved and Totem or Tiki carved.

Call in a professional tree trimming specialist. Depending on the variety of palm, they should be trimmed annually or at least every couple of years.

Most plams have a relatively small, ball-like root ball. Have a good crew dig it up, 'reset it" to a pleasing curved position you like, and water it in well. Brace it for a few months, and don't bury it deeper than the original planting.

http://homeguides.sfgate.com/stabilizing-topheavy-plants-32522.html

I understand that there is a beetle and also a fungus that is attacking palm trees. Especially in California. Make sure it is not diseased or has beetles. If so, it will have to be removed.