Replace delimiter for a particular column in a pipe delimited file

Shell Programming and Scripting
1

I have an input file as below

Emp1|FirstName|MiddleName|LastName|Address|Pincode|PhoneNumber
1234|FirstName1|MiddleName2|LastName3| Add1 || ADD2|123|000000000

Output :

1234|FirstName1|MiddleName2|LastName3| Add1 ,, ADD2|123|000000000
OR
1234,FirstName1,MiddleName2,LastName3, Add1 || ADD2,123,000000000
2

Welcome on board,

What have you tried so far?

3

Replace all || with ,,

sed 's/||/,,/g'