Shaun, who has been in a wheelchair for 27 years, is preparing for a celebrity triathlon and a 10k event.
He says he is relaxed about the procedure and even admits he is relieved to have his right leg amputated, saying: “I don’t need my leg.”
The father-of-three from Lancaster had been climbing up Ben Nevis in his wheelchair when his right leg became trapped underneath his wheel, causing it to break, back in June.
He had been raising money for Help For Heroes, Calvert Trust Exmoor, Back-Up Trust and George’s Legacy - a charity based in Hoghton to offer support and advice to bereaved parents.
Shaun spent several weeks at Raigmore Hospital before being transferred to Lancaster Infirmary.
Now resting at home, the 47-year-old has been informed his leg has not healed and it will need to be amputated.
But before the operation at Blackpool Hospital on September 16, he will take part in the Superhero Tri in Windsor on August 18, as well as the Salford 10k on September 9.
Shaun says: “After nine or so weeks, my leg still hasn’t healed.
“If I didn’t have the amputation, it would take more than a year to recover, so this way I am speeding things up.
“I have been in a wheelchair for 27 years and don’t need the leg.
“Psychologically I am okay with it.
“To be honest I am relieved that now I can see the light at the end of the tunnel.
“Doctors wanted to save my leg, as that is their job, but I see no need for it.
“My wife, Dawn, has struggled more than me. My three children have been brilliant and have kept their sense of humour.
“I have a purple cast on my leg to support the weight and they have painted my toe nails pink!”
Despite his injury, Shaun has been training hard and can’t wait for his next challenge - a triathlon organised by ex-paralympian Sophia Warner, featuring well known paralympians.
The event will be filmed by Channel Four and will be aired shortly afterwards.
Shaun adds: “I have been working hard and I am back up to my fitness.
“This Superhero Tri is held twice a year and it is great to see the people there and their faces when they achieve their goals.
“The challenge was set up by Sophia Warner to encourage individuals with different abilities to take part and realise they can achieve something, whether it be swimming, cycling or pushing themselves in a wheelchair.
“I am also doing the Salford 10k the week before I have my leg amputated.
“This is not going to stop me. I am going to move on and do other things. I have more challenges to do and the quicker I get my leg sorted, the better.”
Following a road accident in 1991, Shaun sustained major injuries, leaving him completely paralysed from his chest down.
Determined not to let his injuries hold him back, he began training in his wheelchair and has completed two UK Obstacle Course Racing Championships and was the first paraplegic to attempt to climb Mount Kilimanjaro, reaching 16,700 feet before having to evacuate.
Last year, he took part in a Twenty 20 Challenge, pushing himself in his wheelchair from Lands End to John O’Groats.
Shaun has also become a motivational speaker, inspiring others in his situation to achieve their goals.
His efforts have not gone unnoticed as he has been nominated for the Lifetime Achiever Award at the Inclusive Companies Award.
The winner is expected to be announced later this month.
He adds: “It is quite humbling as I do these challenges for fun and to help charities.
“The fact I have been nominated is amazing, regardless of whether I win.”