I suspect most people will simply reply "don't do it" because it's cost ineffective and impractical for a small volume.
Let's suppose you actually want to do it.
Biggest question - do they actually want it melted? Or would forge welding it all together be sufficient? Forge welding is much more practical. See Green Beetle youtube videos for forge welding weird stuff together.
For this, you could crush it into small chunks, flux it, and put it under a power hammer. Many forging shops would have the equipment to do it. You would be hard pressed to find someone to do it for less than $100 per pound, but maybe that's not a limiting factor.
Want it melted? Extremely few hobby or small shops will have the equipment for this, since the temperatures required to melt steel are beyond what's easily obtainable with forging setups.
You'll probably want a electric inductive heating setup, like in electroslag remelting. These setups would almost definitely not do anything for a small volume individual.
Some laboratories do small batches, such as for scientific testing of new alloys and such. The cost would likely be very high.
Before this comes up as an option: even a smelter doesn't melt steel, and those run at very high temperatures.
The higher the temperatures, the higher the risk. You can go cheap and get a hold-my-beer dangerous coffee can crucible that explodes when your buddy ignites the thermite in it. Or you work in a controlled lab setup that will probably cost more than just buying fifty times as much steel.
. I think I'm going to tell him the truth and that its not as easy as it seems. I have no experience with it like him and I was curious as well so It was worth asking. Thanks everyone so far for preventing someone else getting killed 
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