I used to think that refilling laser toner was fraught with problems but, having tried it, it's no more or a problem than refilling a photocopier with toner - possibly less so.
We get our toner from click here who supply instructions on how to do it.
I don't know about your printer but our studio Samsungs require you to unfasten 5 or 6 screws, lift a lid, pour in the toner (carefully!!!!) and put the lid back on. A quick shake and back in the printer. Print off a couple of sheets to clean the roller and that's all.
The toner powder from cartridgeco was Xerox brand and gave results indistinguishable from the original.