Air New Zealand 787-9 texture request

I obtained clearance to make an Air New Zealand 787-9 for the following model: the CamSim 787-9, avaible here in AVSIM. The problem is: I can't edit any texture because I can't have any texture editing program.I request this because Air New Zealand is the real-world launch customer for the 787-9 and I enjoy this 787-9 really much.