Walker's two brothers found respect for what their brother did.

Delayed Fast and Furious 7.

“Fast and Furious” seventh installment was delayed after Paul Walker’s death in a car accident in November 2013. The script was rewrote in order to “retire” his character who played the role Brian O’Conner on the films and honored to a final send-off.

Walker’s two brothers, Cody and Caleb, were brought in to act as body doubles to complete new scenes leading to Brian O’Conner’s “retirement” in the franchise. According to a report by India Times, the film used “CGI, carefully chosen camera angles, and the right lighting” to simulate Paul’s appearance. Both Cody and Caleb resemble the body build and the face of their late brother using this CGI or computer generate imagery. They were brought on an acting coach who, with John Brotherton.

Walker Mini Biography

Paul William Walker IV  was born 12 September 1973, Glendale, California, USA. He died on 30th November 2013, Valencia, Santa Clarita, California, USA (car accident).

Walker Parents are Cheryl Walker (model), Paul William Walker III (sewer contractor)
Below are Walker Siblings:

1. Caleb Walker - October 04, 1977 (38), Los Angeles County, California, Estados Unidos, married to Stephanie Branch.
2. Cody Walker - June13, 1988 (27), Los Angeles County, California, Estados Unidos, married to Felicia Knox
3. Ashlie Walker - (born 5 April 1984, London) is a British actress. She has been working in television since the age of ten[1] and has had roles in Bad Girls, Casualty, Doctors, Hollyoaks and A Touch Of Frost.She has appeared in advertising made for television. She has a website at http://www.ashliewalker.com
4. Amie Walker - According to media 46-year-old Amie Kaz Walker is Paul’s half sister, daughter of Mr. Walker Sr.’s previous relation, but Amie was close and adore him her brother just like the rest of them.

Source: 

1. Inquirerdotnet
2. The Free Encyclopedia