which toyota and engine do you have? some are easier then others. some v8 i heard are VERY hard while others are very easy it just matters on the engine.and only advice i can give is try not to brake the contact post on the new one (done that before), and do a look over how to do it in advance and get a repair manual.
On a '92, should be no problem. There is a little more in the way on a 4x4 but it is just 2 bolts, the '+" battery cable and 1 connector to the solenoid. I changed my '86 4runner's in about 45 minutes.