I need help using Solver in Excel with the GRG Nonlinear setting for the following problem:

Create spreadsheets and use Solver to determine the correct volumes to be produced to minimize cost for the following problem. Your company has two trucks that it wishes to use on a specific contract. One is a new truck the company is making payments on, and one is an old truck that is fully paid for. The new truck's costs per mile are as follows: 54 (fuel/additives), 24 (truck payments), 36 (driver), 12 (repairs), and 1 (misc.). The old truck's costs are 60 (fuel/additives), 0 (truck payments), 32 (rookie driver), 24 (repairs), and 1 (misc.). The company knows that truck breakdowns lose customers, so it has capped estimated repair costs at $14,000. The total distance involved is 90,000 miles (to be divided between the two trucks). Cost Per Mile Constraints New Truck = Old Truck 0.6 Total Miles Repair Cost Fuel/Additives 0.54