I have a similar lift on mine. The plug is in an elbow fitting at the rear of the cylender and can be reached from underneath.
I got one of those handy-dandy pump & hose outfits for gear oil that has a barb-clip at the end so it would stay in the hole on it's own, set the jug of fluid on an overturned 5-gal bucket, and pumped till it overflowed. Didn't have to risk life or limb, works good, last long time!
Something else I did was drain the fluid, disassemble the pump (good way to drain it by the way), and checked all the seals and bearing caps. Cleaned it all up, a dab of aviation form-a-gasket on the sealing plates, and topped it off. It used to leak a lot, haven't lost a drop since and works MUCH better than before.
