How to replace special characters in vi?

Hi ,
I want to replace the special characters in the file.
For eg: cat abc
1234/4455/acb
234/k/lll/
234`fs`fd

I want to replace / and ` with the letter a and the output should like below. How to achieve this.
1234a4455aacb
234akallla
234afsafd

Try:

:%s!/!a!g
:%s/`/a/g

"/" and "`" are not special in regular expressions. And you can use almost any non alphanum char as a separator for patterns in "s" command.

Bingo!!

Correct answer dude!!!