I put one on a
L4330 without too much difficulty. That's a smaller tractor in the same series as your
L5030, I think. To avoid a hanging wire along the length of the joystick shaft, I discarded their bulky protective plastic tube and wrapped the plain wire/shaft with electrical tape, like you would a baseball bat handle. It's held for at least five years but if I did it again, I'd find some heat shrinkable tubing to cover it all. I also replaced the set screws that hold the handle to the shaft with stainless ones. Those black ones they provided rusted in no time.
If you're antsy to get it mounted, you could be figuring out where to tap into 12 volts while the kit arrives. That took about as long as anything else for me. I think they only want it hot when the ignition switch is in the ON position. You'll probably end up running a wire with an inline fuse from the ignition switch area over to the joystick area so there's some protective routing involved in that too.
I also shortened the joystick, which was too long beforehand, in my opinion, and the new switched handle lengthens it even more.
Again, this has been awhile so their design may have changed or my memory may have failed me.