If you were good at it, thats the upper range, never used the pyridine route personally, and its the freebase which is used.
The yields based on codeine are fairly widely known to be crap. Was going to test the thiolate route but didn't get the chance, courtesy of a bunch of bumbling idiots screwing things up. But either that or the use of BBr3 would be I'd how I'd go about it (although given you've said you've no background in chemistry, definitely avoid the BBr3 route, its highly toxic)
The mercaptides would be produced via addition of the appropriate alkali metal (I.e sodium) under an inert atmosphere (vessel purged with argon, easily had in disposable cylinders, likewise the regulators from welding stores)
As for the Na, if you can't buy it, there's a rather nifty non-electrolytic method, using the much more easily had magnesium powder, essentially a thermite type reaction between sodium hydroxide and magnesium dust, in a suitably heat-resistant container, it produces a slag of magnesium oxide intermixed with metallic sodium, and it turns out that 1,4-dioxane, a cyclic di-ether solvent, easily produced using concentrated sulfuric acid (often used for unblocking bogs and other nasty holes in the ground of that nature) to dehydrate ethylene glycol (antifreeze, you want the concentrate, not ready-mixed, which is full of water) via distillation.
Be aware that ethers form peroxides in storage, but there is plenty of literature online as to how to get rid of them (they are extremely shock-sensitive explosives), as for testing for them so as to know if they need treating (ethers in general), soak paper in a solution of starch, such as from boiled down potato liquor and then once dried, also in a solution of potassium or sodium iodide, and cut into test strips. Peroxide presence being indicated by a colour change, to a purplish-black colour
The deeper the colour, the greater the contamination, and any discoloration means it should be treated.
(the slag from the thermite rxn is ground, and then refluxed under dioxane, which needs to be dry, given the reactivity of sodium, although, given you are going to need an inert atmosphere anyway for the thiolate demethylation you'll already have the argon tank handy, a portion of the sodium/magnesium oxide slag could be used for dessication of the dioxane, and under the dioxane, the Na will melt out.)
Edit-should mention I have no formal background in O-chem, trained myself, I'm on the autistic spectrum, comes with weird and oddball interests and along with botany and mycology, toxicology, molecular biology, that was kinda what got drawn out of the pot at birth.
Somewhere along the line something just decided that the world either needed one more guy who can't help but spend way too much of his income on a lab, or it needed another thorn in it's side, depending on who you'd ask
Edit 2-for the metallothermic production of Na, you'll want to weight down the lid of the crucible or other vessel used, to prevent the metal vaporizing away in the heat of the reaction.
