I have never handled beef leaf lard, but have rendered the pork fat I received as part of a quarter hog I bought last fall. The easiest way for me to render it was to use a slow cooker. It is a long process because you have to do it at a low temperature, so it was the best way for me to leave it unattended while it did its thing. Once rendered, I poured the liquid fat into jars and either froze them or stored them in the fridge. The brown crispy bits left behind provided a nice porky crunch as a topping for salads, eggs, etc. They could also be used in place of cooked chopped bacon. It was a smelly process once the fat warmed up, so if you don't like the smell of beef fat, you will want to have good ventilation for the rendering.
Let us know how it goes for you.