Riello mectron 3m oil burner oil leak?

I have a Riello mectron 3M oil burner and it has a slight oil leak that seems to be coming from the motor shaft that drives the oil pump, it leaks about an ounce a day but the furnace runs fine. My question is, can I obtain a oil pump o ring kit and do it myself or should I call a tech? I have the Reillo oil pump manual and it appears over time the o rings have just worn out. I understand the Riello mectron 3m was replaced by the Riello F3 in 1990. Any help would be greatly appreciated. Thanks in advance for your help.