Given that your guitar is somewhere between a Strat and a Tele, a combination of the methods are required. Some of the reissues already have shielded pickguards: Is that the case with yours?
Here is the inside of an original '67:
Looks like the hardest part would be the channel from the pup area to the control cavity. Looks like it (the original) might be a pocket rather than being drilled, it could be a challenge. I routed out a channel in my Squier '51, but that was a $79 purchase, you may not want to route your $1000 investment. You'll have to open yours up to see. If it's drilled, you just make the foil as neat as possible (like in a Tele), if it's a cavity, you'll be doing some finger stretches to get in the pocket. The pickguard is all Strat methodology.
More specific methodology than that shouldn't be required.
Ux has got you on the right track already. The only thing I would add is that the difficult part, as he describes, might be easier using shielding paint instead of foil, as it's easier to get the paint into small areas. You could use the paint for the whole thing, or just for that area, so long as you ensure continuity with the rest of your shielding job.
The original instructions also cover the use of shielding paint. It may not be as effective as copper foil, but it does have its advantages in guitars with small holes, etc that need to be shielded.