The dealer CAN adjust the values for the TPMS, but they generaly won't. There's a liability issue with mucking around with / defeating safety related items on a vehicle.
It's done with the StarScan tool, and don't be surprised if they expect you to pay for the service. It should take them 10 minutes, but they often charge for a full hour. I didn't get mine done yet -- I bought a slightly higher rated tire that can handle 65 psi, so I can keep the pressure just above the TPMS warning threshold.
'08 3/4 Mega Cab Laramie 4x4, 6.7L automatic.
305/65/17 BFG T/A-KO on stock suspension.
Extang Solid Fold tonneau cover, Line-X, plus other minor improvements.