In order for the easy lube process to work, and I use that term lightly, there are several things to consider.
You need to be turning the wheel as you pump grease in.
You will need to pump a lot of grease to reach the outer bearing because the grease that you put in goes to the inner bearing first.
You will still have the old grease in the cavity.
You risk blowing out through the seal and contaminating the brake shoes.
You won't know the condition of the old grease.
You won't know the condition of your bearings.
It's absolutely best to buy some new grease seals, good bearing grease, take it apart, clean and inspect the bearings and properly grease by hand.
JMO.
Peace
Dave