I think just leave it and let it age naturally, especially if it's a higway 1, the body will age along with the neck and eventually you'll have a good worn in guitar with a story behind it, aging the neck purposely straight off the bat might tarnish your relationship with it in the years ahead (Dr Phil eat your heart out!)
Seriously though this question comes up a lot on the Telecaster forum and the general consensus seems to be to either live with it and let it yellow itself, or put in a fair bit of effort and refinish it with a tinted lacquer.. You can get cans of it from Reranch, Stewmac etc. maybe the same stuff Wez suggested, didn't check the link..
You could do it partially, just scuff up the old finish and spray on the new one over the top.. Or do a full refinish and strip the neck completely and finish it with a vintage tinted lacquer (also gives you the option of going nitro if you're that way inclined)
Seems like a lot of effort for a small aesthetic difference though.