I have never done this before and I am trying to help a friend and I have to be extra careful. So this is the situation,
My friend is a British Citizen and my he would like to bring his parents over for a short trip in a couple of months to the UK. He is ready to apply through a solicitor with a fee but I am trying to save him some money being the friend that I am..

1) He has already got a letter from the council stating that there is enough space in his house for his mom and his dad.
2) he has got his payslips for 3 months showing fulltime employment.
3) He has got enough money in his bank (how much would that be actually for 2 people?).
4) Does his parents need to show any bank balance.
5) His parents has a refusal in their immigration history when they were refused for lack of enough funds the last time they tried applying from India for coming to britain on a visitor's visa in 2008.