How should I maintain the dryer's internal lint and the exhaust vent over time?

Lint inside the dryer cabinet and in the exhaust vent should be removed every 2 years, or more often depending on dryer usage, and this cleaning should be performed by a qualified person. The water inlet hoses should be replaced after 5 years of use to reduce the risk of hose failure, and should be inspected periodically for bulges, kinks, cuts, wear, or leaks. (Page 25)