Homeowners can safely replace ceiling fan parts safely on their own with the correct parts. The biggest precaution that must be taken is to make sure that the fan does not have live power prior to replacement.
In replacing the pull chain, the wires inside the housing should be marked to ensure they are put back correctly in avoiding a fire or other electrical problems.
In the case of fan blades, it is helpful to have a second person to help steady the fan while the blades are removed and replaced. If another party is unavailable to assist, the fan should be taken down.
These are the two ceiling fan parts most often replaced; homeowners can refer to the owner's manual or contact the manufacturer when unsure about other fan issues.