I know this is an old thread, but there's not a ton of info on the net about the 680 oiler and the pressed on brass bushing/ washer. Just had to replace the small hose that leaves the pump and goes to the "Y". There's no need for special tools. Like said earlier, the 2 holes are threaded. Find bolts to match the threads and evenly screw them in on each side to slowly back off the bushing. To re-install, I just greased the crank well and beat the bushing slowly back on with a deep socket. This is the least fussy, hardest working saw I've ever experienced. I've worked on many different saws and this thing is built very well.