[buzzkillwill]

It is not necessarily hard to change the gears, it is just hard finding all the parts to do it. I am still trying to find inner and outer pinion bearings and a new crush sleeve to finish my gear swap.

The biggest problem is getting the ring and pinion (aka gears) as Nissan doesn't sell them individually and noone makes after market ones yet.

Besides the gears, you'll need to reflash the ECU and (IIRC) you lost cruise control function. Also, your speedo will be off. RB'sTitan switched his gears and I think those were his findings.