Well it can be easy. There are two options. Platform io or xloader.
You can already flash your ramps so flashing the rambo is no harder.
Our ready to go firmware is here, and it sets the driver current even https://docs.v1engineering.com/electronics/marlin-firmware/
We have worked very hard to make all of this as easy as possible and there are a couple of really smart people here to help. Please be sure to answer any question asked of you to make it easier and keep everyone interested in helping.