Name and S/o Name problem in excel sheet

[AVG123]

Friends i have a sheet of excel which is full of data......now i have one problem please anybody solve it.........

Problem is i have a field in which is full of name of employees in one cell (name and s/o)

Example:- "Gyaneshwar Verma S/o Sh. Sushil Kumar Verma"

"Rajesh Kumar Sharma S/o Sh. Ram Singh"

"Ravi Kumar S/o Sh. Puran Singh"

"Deepak kumar Sharma S/o Sh. Rahul"

now i want only "First Name" not S/o
i dont want text after S/o.........please friends solve this problem