you have not said if it is Fuel leaking (usually the delivery valve O-rings) or Oil (leaking usually from the bottom plate, side cover or throttle or shutoff shafts).
I would not trust the O-ring job to a regular mechanic.
If it is the Delivery Valve Seals/Fuel leak even if you do not do the job yourself you could look in the Repair Links and get some idea what needs to be done. The same with the Oil leaks.
Repair Links Fast navigation
http://www.peachparts.com/shopforum/diy-links-parts-category/146034-fast-navigation-do-yourself-links.html