Where I could find this specific Camera Lens Part?

Okay, I'm looking for the second to front lens of a Nikon DX AF-S NIKKOR 18-135mm 1:3.5-6.5G ED lens system, It also says Nikon DX SWM ED IF Aspherical (infinity)-0.45m/1.48ft (0 with a / through it) and Made in Thailand. I looked almost everywhere on the web, and couldn't find the piece, or even the name of the piece. Could anybody help me out?

You will first have to visit a camera repair shop and see how they order parts they need.

Usually unless you have the tools, training and experience, replacing the front element on any lens is not recommended

Just bring the lens to the Authorized Nikon Service Center in your area and have them replace the part for you.