It just pulls off. Make sure you mark its position. If the rotor has never been off the car before, you may want to try to gently pry it on both sides. And if you are replacing it, make sure you get a Suzuki rotor - some cheap aftermarket ones go one 3 different ways. You'll notice on the triangular housing that the rotor slides on to, there are two long edges and one short one.
Yes - if you have installed the distributor to a different cylinder, etc., you will need to remove it, get the engine to cylinder#1 on its compression stroke, make sure the crank is at the 0 mark, and put the rotor at the #1 position. On the 8v, this is usually at about 11:00.