If it's just an oil change, take wheel, mudguard, forks off.
When you undo top bolt on forks be careful as it is spring loaded so keep a good grip on the ratchet and fork when undoing it or you'll lose your teeth.
May even be an idea to slacken off the tension adjusters first.
If you haven't already bought it, i would seriously suggest buying 15w oil, it makes a big difference to handling in my opinion.
Put the correct amount of oil in first with the fork fully extended (after pumping the old oil out as much as possible), there are 2 levels given so get the correct one, 98/99 models don't have adjusters so need more oil, then you need to get the air gap between the oil and the top of the forks the same so they are equal. Not sure what the gap is off the top of my head?
Then put it all back together.
When putting forks back on put the spindle through the forks so you can make sure the fork legs are straight before properly tightening them back up, and use a torque wrench.