Not difficult at all to do , first obtain Ryobi primer /fuel line kit from your local distributor , then remove air cleaner cover (pops off with fingers) then drain all gas from fuel tank back into storage tank , locate the two Phillips head screws next to primer bulb and remove them , careful not to drop them !! remove old bulb from ring and replace with new bulb from pkg. then using a clean cloth , carefully wipe out sealing grove where bulb seats down (I guarantee its dirty) when all clean , place bulb down in grove and make sure it seats well then secure with ring and replace screws (don't over tighten) you might as well replace the fuel lines as they come in kit , instructions are on pkg , I do suggest doing one at a time to not forget how they go , and do use the new fuel filter that's inside pkg too