First of all, check your pickups. Do they have at least 4 wires coming out of each pickup? You need to have at least 4 wires from each pickup to split the pickups. If you have both pickups with at least 4 wires you can split both pickups. If only one pickup has 4 wires you can split only one pickup. The Seymour Duncan website has wiring diagrams on it for splitting pickups that may or may not be easy for you to follow.

I have some guitars with split pickups and some of them are good at doing it, while some are not great sounding, to me, when split. None of my guitars, when split, sound like a stratocaster or telecaster. So, for me, splitting the coils is something I haven't done when putting high quality pickups in guitars. I just put them in and wire them as full humbucking pickups and solder the two extra wires together from each pickup and tape them up. Then I wire the new pickups in just like the ones I take out, following the existing wiring scheme that the guitar has, unless the way that the guitar is wired up stock is all messed up - which is usually not the case.

If you want to split them, follow the directions on the SD site, and if you find this too difficult, get everything put together and bring it to a good guitar tech and have him solder up the connections. If you try to wire it up yourself, it might be wise to leave all of the wires longer than you need them by a fair margin, in case you have to take it to someone to have it wired up. The correct way of wiring it might require that the wires be longer than the way you cut them when you tried to wire it. You don't want to have to have additional length soldered on and all of that type of thing will cost you more in the end to get done.

If the wiring job looks over your head after you look at all the wiring diagrams and have selected the correct parts, you might find that it is well worth the cost to take it to a tech that is knowledgeable of wiring up all sorts of complicated wiring schemes. These guys are fast and know what they are doing. I don't imagine it would cost you much to have it done. If you bought the pickups from a place that has a tech, or the guitar, they might cut you a break on doing the job.

I think that those pickups would sound very nice in an SG. I have that set in a guitar and it is one of my favorite guitars. It actually has split coils too, but I almost always play it as a full humbucking guitar. Maybe if I was really playing loud I would notice the coil split more and it would be more useful.

The Gibson web page might also have a good wiring diagram for wiring up the split pickups with two volume and two tone knobs; in fact I think I saw the diagram on the Gibson site but was looking at a different scheme.