A lot depends on the timber, but for most European hardwoods it's really not difficult. Mark up the leg in pencil where you want the taper, clamp the leg upside down (i.e. toe uppermost) in your vice with about 100mm sticking up, saw on the waste side of the line, when you get near the vice raise another 100mm up, repeat until you've completed the cut, clean up down to the line with a bench plane, mark the other taper on the adjoining face and do the whole thing again, this time use the off-cut from the first cut as a packing piece to keep it square in the vice. A cheap hard point saw from B&Q is perfectly adequate.
As I say, if you're working with oak, elm, ash, sycamore or something similar then there's absolutely nothing difficult about this at all. If you were working with ebony or lignum vitae it would be a tougher job. You don't need axes or drawknives, just the basic tools you've probably got lying around.
One final thing, "joint first, shape second", so cut the mortice and tenons before tapering the leg, that way you've got more square and true reference surfaces to work from.
Good luck!
