Here's a step by step video on how to replace the timing belt, waterpump, camshaft and crankshaft seals, idler pulleys and tensioner on a Toyota or Lexus with a V6 engine.
Procedure is the same for all 1994-2006 1MZ-FE (3.0L) and 3MZ-FE (3.3L) engines, with the newer engines differing only in the timing belt tensioner bolts.
Procedure is straight forward starting with the removal of the dog bone mount, engine support bracket, alternator and power steering belts, crank pulley (harmonic balancer) and timing belt covers.
Once access to the timing belt is achieved, the tensioner is released so the belt can be removed. The camshafts should be removed to get to the waterpump, otherwise two studs running through the waterpump have to be removed.
Special tools required are an impact wrench and air ratchet (not mandatory), a seal puller, a pulley puller, torque wrench, and a crankshaft and camshaft holding tool.
This job should take 4 hours for a DIY'er with moderate mechanical aptitude. The Aisin timing belt kit with waterpump from RockAuto was used.
After the removal of the cam and crank bolts, the hardest part of this job was dealing with the rear camshaft seal and aligning it with the marks on the timing belt. Access is tight near the fender wall and removing the power steering fluid line and reservoir is recommended.