I change mine every couple just cause I have nothing else to do
When I run out of crap to buy or am in the moment of satisfaction of the bike in its current state...I regress to unnecessary maintenance.
That being said, if you are bored and it has been minute- go for it. You can clean stuff while you are in there which will add another hour to a relatively simple process. (which is also another hour away from household 6)
2001 #62. Ohlins rear/valves, Micron high mount, HyperPro damper, SharkSkinz, Tyga billet triple clamp, Tyga Carbon Fiber fender and hugger, Ti bolt/custom subframe/alien motion 8 cell diet, 15/41 520, COP conv. PCIII, Venhill lines, modified air box, turn signals in headlights...<deep breath> ZG Touring windscreen, Tech G rear sets, CRF450 rear master w/HRC cover, Tokico 6 pots w/V-pads, CRG Bar end mirrors, PSR Shorty levers-use only clutch, wanna-be basic racer paint, Roman Gold PC wheels