Ben Melham has already begun a three-month mission to strip his body weight to 51kg to ride Golden Slipper winner She Will Reign in the inaugural $10 million Everest.

The Melbourne rider has committed to a program to partner the Gary Portelli-trained filly at the light weight in Australia's richest race at Randwick on October 14.

He says he has started this far out to ensure he goes about it the right way with his diet and training.

Craig Williams will take the ride on the filly when she resumes in the Moir Stakes in September with 50kg.

"A lot of people might think you're silly starting this far out, but at the end of the day if you can just time it right and be as prepared as you can mentally to be at the target weight on the day, it can be easier," Melham told RSN927.

"Whatever way you look at it, it's going to be a tough task. I'm prepared mentally for that. I know it's going to be a tough road ahead but hopefully I can reap the rewards."

He is working closely with a dietician and fitness trainer.

Melham said he would have to lose five to six kilos off his base weight for The Everest.

He said he had to set goals along the way and reduce his weight gradually.

"It is sort of my absolute minimum. It has have to be done properly and with so much money on the line you want to be getting there in the best possible order you can," Melham said.

"When I saw my dietician, I did see her a long way out just to make sure that she thought it was physically possible for me to get to that weight.

"We did some tests and stuff like that, and I certainly couldn't get any lighter than that but she did think it was an achievable goal."